Auckland enjoyed a belter of a summer in 1948, but nobody was swimming—they knew a killer lurked in the city’s tranquil harbours. The poliovirus might be just a short ribbon of RNA wrapped in protein, 2500 times thinner than a human hair, but that year, it took 52 lives. This epidemic began in November 1947 with a single case in Auckland, but doctors recognised the symptoms of polio—fatigue, nausea and fever—from bitter experience.
Has anyone died after receiving a COVID-19 vaccine? TAP TO FIND OUT...
“Yes, but not because they received the vaccine,” says vaccinologist Helen Petousis-Harris. As of January 14, the Norwegian Medicines Agency reported that 23 people in the country who had received a vaccine had died. All the fatalities were nursing home patients over the age of 80. About 45 people die every day in Norwegian nursing homes. “These deaths do not represent an increase over what would normally be expected,” adds Petousis-Harris. Norway also keeps detailed records of all adverse reactions to vaccines, whether a sore arm, flu-like symptoms, or an allergic reaction.
Polio epidemics had struck New Zealand at least once a decade since 1914. In 1948, the disease brought much of the country to a standstill. Since poliovirus spreads in faeces and in saliva, people were warned to stay out of Auckland’s sewage-tainted harbours. Schools stayed shut after the summer holidays and didn’t reopen until the middle of April. All the same, the disease spread throughout the North Island until, by winter, Wellington wards were full. The Correspondence School ramped up its radio classes from 40 a month to 40 a week. Kids younger than 16 were confined to home, and public gatherings were cancelled. Women stood on the front porch and shouted their grocery orders to patrolling shopkeepers, who later dropped the goods over the fence. By 1949, polio was rife in the South Island, too.
More than 70 per cent of people who contract polio don’t know it: the virus most often stays put in the gastrointestinal tract, where it does no harm—in fact, it grants its host lifelong immunity. But in a small fraction of cases—fewer than one per cent—the virus invades the nervous system, where it sets about destroying the spinal cord. Some patients endure creeping paralysis, usually in the legs. In severe infections, the virus attacks the muscles of the diaphragm, leaving the sufferer unable to breathe without help from a mechanical ventilator.
Will the vaccines make me sick with COVID-19? TAP TO FIND OUT...
No. The SARS-CoV-2 genetic material used in various vaccines is non-infectious. But activating your immune system can induce mild flu-like symptoms for a day or two.
And it was predominantly children who occupied those ventilators, enduring weeks on their backs encased in such “iron lungs”. Only their head, sealed by a rubber gasket around their neck, protruded, while the machine alternately boosted and vented the air pressure—much like a milking-plant vacuum pump—inside the chamber. Strict quarantines meant even their parents couldn’t visit them. Many kids hobbled home to recuperate in leg splints. Some never took them off again. Many adults, meanwhile, died not from their first bout of polio but from post-polio syndrome—muscle weakness and paralysis that arises years later.
There’s no cure for polio. Between two and five per cent of children and 15 to 30 per cent of adults who contract the disease die. According to Health Department records, polio infected nearly 9500 New Zealanders between 1915 and 1961. It killed 835 of them.
And Aotearoa wasn’t the only country grappling with polio. In the United States, there were 119,000 cases of the disease and 6600 deaths between 1951 and 1953. In 1952 alone, 21,000 people were left paralysed.
Back in 1916, people thought they could keep polio at bay by hanging mothballs around their necks and rubbing rosemary on their skin. In the real world, though, our bodies employ a different defence.
Why do viruses mutate? TAP TO FIND OUT...
For any organism, it’s a case of adapt or die, and viruses are no exception. As people’s resistance to a virus grows, it puts pressure on the virus to beat that resistance. It does this through mutation, which is not a deliberate act—more of a lucky break. Like everything else, viruses replicate by making copies of their genetic material, but mistakes happen during the copying process, so that the new version might have a different trait. This can go either way for the virus. The new trait may be detrimental, in which case, the new variant fizzles out. But it might give the virus an advantage, in which case it becomes more successful than previous strains.
Once a virus is inside you, it hijacks your cells to multiply and spread. Your immune system fights back with various types of white blood cells, antibodies and chemicals, explains University of Auckland vaccinologist Helen Petousis-Harris. “Macrophages lead the charge,” she says, by ingesting and dismantling the virus particles. Those broken bits of virus are called antigens (short for “antibody generator”), and your body rallies specially adapted white blood cells called lymphocytes to attack them. B-lymphocytes produce antibodies that pick off the pieces of the virus left behind by the macrophages, or they inactivate the virus and target it for destruction, while T-lymphocytes attack your own cells that have already been infected.
The first time your immune system encounters a new virus, it has to start pretty much from scratch. It takes a while to learn about that particular pathogen, but that lag time is all a virus needs to secure a foothold and start spreading. The upside is that, once your immune cells have battled a virus, they usually remember it, sometimes for years, sometimes for life. So when the same pathogen appears again, your immune response is swift and efficient.
A vaccine works by giving your immune system that identikit in advance, so it can lock on to the target early in infection, shutting it down before it can spread too far.
Will these vaccines work on other variants of the virus? TAP TO FIND OUT...
All the COVID-19 vaccines so far are based on what the virus looked like—and how it worked—a year ago. Since then, it’s been mutating. The South African variant—501Y.V2—is a particular concern, because it might resist the antibodies people produce after they were infected by a previous variant. So far, research shows the vaccines still work on the new variants, but may not work as well. For instance, Novavax’s vaccine has proven to be 86 per cent effective against the UK variant, B.1.1.7, but only 60 per cent effective against the South African one.
Vaccinologists began trialling polio vaccines in the 1940s. The first task was to sift through the 125 known strains of the disease. Jonas Salk, head of the Virus Research Lab at the University of Pittsburgh, sorted the strains into three basic types, then came up with a vaccine that contained poliovirus intact enough for the immune system to recognise it, but sufficiently weakened with formaldehyde that it couldn’t cause an infection.
How effective are these vaccines? TAP TO FIND OUT...
“Very,” says Petousis-Harris, though she points out that no vaccine is 100 per cent effective. “Between them, trials of the Pfizer and Moderna vaccines were conducted on around 75,000 people. Most cases of COVID-19 occurred in those who got the placebo instead of the vaccine. These vaccines had around a 95 per cent success rate. When cases did occur in the vaccine group, they were mild.”
What don’t we know about these vaccines? TAP TO FIND OUT...
“As with any new vaccines,” says Petousis-Harris, “we don’t know how long they will provide you with protection from SARS-CoV-2, although we do know that people can retain antibodies for months and years. Neither does anyone know if the vaccine prevents anyone from still carrying COVID-19 or spreading it to others.” Some vaccines prevent disease but not infection; a person immunised against whooping cough won’t get sick, but can become infected and pass it on.
In 1952, he trialled his jab on himself and his family, before testing it on a wider group of people. Their immune systems produced antibodies—a sign they were safe from serious infection. Salk’s vaccine went nationwide in 1954, through a mass inoculation of schoolchildren, and for a while it looked like the curse of polio had been broken. Then people started getting sick.
Why has the Government spent $75 million on vaccines for developing nations? TAP TO FIND OUT...
Because ethically it’s the right thing to do. And because medically it’s the smart thing to do: wherever countries are failing to manage the coronavirus adequately, there’s a risk of new COVID-19 strains evolving—as they did in the UK, South Africa, and Brazil. There’s a possibility that any new strain might be resistant to the vaccines already developed, which would be a massive setback. So it benefits us all to get as many people vaccinated worldwide as quickly as possible.
One of the five companies licensed to manufacture the vaccine, Cutter Laboratories, had failed to properly kill the virus in their shots. (US health authorities had earlier dismissed an employee’s warning that the Cutter vaccine was infecting subjects with polio in trials.) Around 120,000 faulty batches had been delivered to nurses who were unwittingly injecting children with live polio. Many people fell sick, while infected but asymptomatic children spread polio anew across the States. It was one of the worst pharmaceutical disasters in US history: 169 people were paralysed and 11 died. The vaccination programme was suspended, as were drives in the United Kingdom, Sweden, West Germany and South Africa.
What if I’ve already had COVID-19? Do I still need the vaccine? TAP TO FIND OUT...
University of Auckland research found that some people who’ve already fought off COVID-19 have the antibodies in their immune system up to eight months later, which is encouraging news. Nevertheless, the US Centers for Disease Control and Prevention agency recommends that even previously infected people still get vaccinated. People may need to get vaccinated against new variants, too.
The loss of public trust meant some 30 per cent of Americans were still unvaccinated two years later. Fully a third of new polio cases were in teenagers, yet they were precisely the demographic most reluctant to accept the shot. Even the spectacle of Elvis Presley getting it live on The Ed Sullivan Show in 1956 failed to move them. The fear of missing out finally achieved what The King couldn’t. “No shots, no dates” was a dance ban conceived and enforced by Teens Against Polio, a national youth body. Anyone who couldn’t produce a vaccination card didn’t get through the door.
What is 'herd immunity'? TAP TO FIND OUT...
Herd immunity means a virus can’t spread because it keeps encountering people who have developed antibodies against it—either through prior infection or vaccination. Once enough people in a population are no longer susceptible, the virus fizzles out. Herd immunity doesn’t actually mean you’re immune to the virus itself. It just reduces the risk that you’ll come into contact with an infected person. How many people must be immune to achieve herd immunity? It depends on how infectious a virus is. Modelling generally shows a herd immunity threshold for COVID-19 of between 60 and 70 per cent.
In the late 1950s, Albert Sabin developed a new vaccine that protected against all three polio types by presenting the immune system with a live, but weakened, poliovirus. It was this vaccine that finally drove polio from New Zealand, through a national immunisation programme that began in 1961. People subscribed in their droves, and the last known community case in New Zealand occurred in 1977.
Could we achieve herd immunity against COVID-19 in New Zealand? TAP TO FIND OUT...
It would need virtually complete national uptake of the vaccines, and surveys aren’t encouraging: a Massey University study found in 2020 that while 74 per cent of New Zealanders said they would get vaccinated against COVID-19, only 56 per cent were prepared to put their names on a list, 13 per cent said they had no intention of getting vaccinated, and 22 per cent were “neutral”. In a University of Auckland survey in 2019, 30 per cent of people voiced “decreasing confidence” in vaccines. Childhood immunisation rates in New Zealand still languish below herd immunity targets.
Sabin’s vaccine is still in use today. Being much closer to the real thing than Salk’s inactivated shot, it stimulates a much stronger and more enduring immune response—four doses administered throughout childhood give protection for life. It’s been so successful that cases of naturally circulating, or “wild”, polio have fallen by more than 99 per cent across the world since 1988 (although it’s still endemic in Afghanistan and Pakistan, which report dozens of cases every year). Wild type-2 polio was eradicated globally in 1999, and no cases of type-3 have been reported anywhere since 2012.
That wasn’t quite the end of it, though: there have been seven cases in the vaccine’s 60 years of use in New Zealand where that live virus has caused an infection. But, in 2002, a new inactivated polio vaccine put a stop to vaccine-derived poliovirus infection in this country.
The story of the polio shot exemplifies vaccinology’s evolution from conjecture to celebrated science. Many early polio vaccine trials had been conducted with no government oversight, no peer review, no protocol, no appraisal by medical schools. But the Cutter scandal brought an end to that cavalier approach: in 1955, a series of congressional hearings in the US resolved that vaccine regulation was henceforth a public health priority.
The US government imposed laws that lifted, and locked in, vaccine production standards. Polio vaccinations resumed that year, and a dubious public was reassured by plummeting polio cases: in 1955, there were 28,985, and by 1957, just 5894. By 1959, another 90 countries, including New Zealand, were using the vaccine.
Vaccine trials today are strictly controlled and monitored by both government and industry. Their methods and results are checked by other vaccinologists—a process called peer review. In New Zealand, it’s the job of the Ministry of Health watchdog Medsafe to evaluate new vaccines and monitor the performance of existing ones. It reviews clinical and epidemiological studies from around the world and case reports from its overseas counterparts.
Will it be compulsory to get the vaccine? TAP TO FIND OUT...
Not in New Zealand. This is a constitutional minefield: in the same breath, legislation confers upon citizens the right to the highest standard of healthcare, while granting them freedom to refuse medical treatment. That said, in 2018, the New Zealand Supreme Court may have laid a precedent. While it ruled that water fluoridation was a violation of the right to refuse medical treatment, it also found that some public health measures could override that right where they are clearly justified. So while the Government probably could make the vaccine compulsory, the legal consensus is that it won’t.
Vaccines are probably the crowning achievement of medical science—more than 20 crippling, previously fatal diseases are now preventable. According to the World Health Organization, vaccines currently save between two million and three million lives every year. In January, the University of Cambridge and Imperial College London released a study which estimated that a child born in 2019 has a 72 per cent better chance of survival against 10 major fatal diseases, thanks to vaccines, than an unimmunised child.
So how would the Government encourage people to get vaccinated? TAP TO FIND OUT...
The Government has been silent on incentives or sanctions. In a Massey University survey, people supported various restrictions on unvaccinated people, including travel bans (61 per cent), restricted entry to public places (57 per cent) and curbs on their children attending school (50 per cent). People were less keen on higher tax rates (28 per cent) and reduced pay (30 per cent). Employers could be within their rights to make COVID-19 vaccination a condition of ongoing employment. Travel agents have argued for “vaccine passports” to prevent unvaccinated people from taking international travel.
The study of childhood immunisation programmes in 98 countries found that, between 2000 and 2019, they had prevented 37 million deaths—mostly among children under five—from 10 diseases, including measles, rotavirus, human papillomavirus, Haemophilus influenzae type b (Hib) and hepatitis B. Projecting those figures, the researchers concluded these vaccines will go on to save a further 32 million lives by 2030.
It took nearly 25 years to develop a safe polio vaccine, but the first COVID-19 vaccine took just under a year, thanks to strong political will, rapid technological advances, and an extremely wide testing pool.
Rather than being celebrated, however, this achievement is approached with suspicion. For some people, trust in pharmaceutical research and the scientists and governments that oversee it remains broken. The fiascos that marred the rollout of the polio shot continue to feed fears about vaccination, even though trials today demonstrate a whole other order of sophistication and safety.
Who will get the vaccines first? TAP TO FIND OUT...
This depends on whether we have any community transmission or clusters at the time. If we don’t, border and quarantine staff and high-risk health workers come first, along with their household contacts. Then come front-line public servants and emergency services staff. Then the broader health and social services workforce and the general public, with priority given to older people and those with compromised health. Should we relapse into widespread community transmission, aged-care residents, and the wider public over 65 years old and people under 65 with underlying health conditions will go to the top of the queue.
On reflection, “Operation Warp Speed” probably wasn’t the smartest name for the US’s COVID-19 vaccine programme. It does sound a bit… hasty. Some people are concerned that safety may have lost out to urgency. More than half of New Zealanders say they would be uncomfortable getting a vaccine that was “rushed” into production. However, drug companies are required to put their COVID-19 vaccines through all of the same trials as they would any other medication or shot, including a three-phase testing process on humans. (For more on these phases, see “How are COVID-19 vaccines tested”.)
How will we get everybody vaccinated? TAP TO FIND OUT...
The logistics of a national vaccination programme are daunting, but we’ve done it before—with polio, for starters. “More recently, there was a mass campaign to vaccinate everyone under the age of 20 against meningococcal disease,” says Petousis-Harris. More than a million New Zealanders now get the flu shot every year, in the space of mere weeks. The Ministry of Health says it will hire and train between 2000 and 3000 extra staff to scale that up. A handbrake, in the case of the Pfizer/BioNTech vaccine, will be having enough ultra-cold fridges to store it in—the ministry has already bought nine –80ºC units.
As this issue went to print, according to the World Health Organization, there were 58 vaccines in development, and 10 that had secured regulatory approval. New Zealand has negotiated to buy vaccines from four different companies— Pfizer/BioNTech, Janssen Pharmaceutica, Novavax and Oxford/AstraZeneca—all subject to the vaccines passing clinical trials overseas and gaining regulatory approvals in New Zealand. (See sidebar, below.)
BioNTech started work on its vaccine before COVID-19 had even left China. Moderna designed its vaccine in the 48 hours after Chinese scientists published the virus genome, based on work its researchers had previously done on a shot for MERS (Middle East Respiratory Syndrome). The rest of the intervening time has been devoted to testing—which has proceeded more quickly than usual simply because study subjects were readily exposed to SARS-CoV-2, the virus that causes COVID-19.
No other vaccine has been developed with the same support, points out Mark Toshner, a consultant respiratory physician and lecturer at the University of Cambridge.
“Next time somebody expresses concern at the astonishing speed the vaccine trials have happened at, point out to them that ten years isn’t a good thing, it’s a bad thing.”
Will the vaccine alter my DNA? TAP TO FIND OUT...
No. mRNA vaccines never enter the nuclei of your cells, where you keep your DNA, and nor do they carry instructions to allow them to integrate into DNA. Vector vaccines introduce adenovirus DNA into your nuclei, but it can’t replicate in there. This myth probably arose because some RNA retroviruses, like HIV, can insert a copy of their RNA genome into the DNA of a host cell, but SARS-CoV-2 isn’t a retrovirus, and mRNA vaccines don’t make the protein necessary to get RNA into your cell nuclei.
“It’s not ten years because that is safe; it’s ten hard years of battling indifference, commercial imperatives, luck and red tape,” he wrote on The Conversation in November. “It represents barriers in the process that we have now proved are ‘easy’ to overcome. You just need unlimited cash, some clever and highly motivated people, all the world’s trial infrastructure, an almost unlimited pool of altruistic, wonderful trial volunteers and some sensible regulators.”
Will the vaccine connect me to the internet? TAP TO FIND OUT...
No. (A claim circulating on social media is that COVID-19 vaccines contain hydrogels that themselves carry sensors that will harvest your data and send it to the internet. Hydrogels are real chains of molecules being investigated for biomedical and bioengineering research. A US company, Profusa, is trialling hydrogel-borne sensors as a way to monitor oxygen levels in body tissues. The sensors announce changes by emitting a faint fluorescence. An electronic patch on the patient’s skin detects that fluorescence, then transmits the information to a nearby computer.)
Yet, despite all the rigorous testing and the advances in vaccine technology, public acceptance seems to have leapt backwards. Surveys tell us that around a third of New Zealanders are either agnostic about a COVID-19 vaccine or hostile towards it, even as they go about their lives unbothered by diphtheria, tuberculosis, tetanus, rubella, mumps, measles, polio, Hib disease, whooping cough or smallpox. As the benefits of vaccines fade from people’s memories, myths about their risks occupy that space.
And it’s not just science that has changed in a century. The world has changed, too. At the time of writing, SARS-CoV-2 has killed more than 2.4 million people—well over 50 times the number who died in polio’s darkest year. But in 1948, nobody looked at a four-year-old fighting for their life in an iron lung and called it a hoax. Nobody marched against social distancing, nor did they hold polio parties to spread the virus.
Suspicion of vaccines, perhaps, is due not to their failure but to their immense success. As well as wiping out diseases, vaccines have erased our memories of the horrors we faced, the disabilities we lived with, and the losses we mourned.
Update: This story was corrected on March 20, 2021 to clarify that post-polio syndrome is not a reinfection by the polio virus, but a complication arising from damage initially caused by the virus.