Why are people afraid of the Covid vaccines?

They have been produced in record time and with new techniques. Although there is no such thing as zero risk, we asked experts to comment on the most common concerns about their safety and side effects

ROCÍO MENDOZA

Monday, 14 December 2020, 13:29

Dates have now been set for authorising the first two Covid vaccines which will be used in Spain: 29 December and 12 January. Europe will enter 2021 with the hope that a new drug will slow down the pandemic that has taken so much away from us. However, even though we know these vaccines are going to be authorised and will be available very soon, some people are still wary of them. The first time the CIS sociological research centre carried out a survey about whether people wanted to have the vaccine as soon as it was authorised, a disheartening 40 per cent said no. That says a lot, but it hides even more. Many people still have doubts and fears, so we have set some of their concerns out below and asked doctors, researchers, scientists and manufacturers to respond to them.

"They've produced it too fast: Shouldn't it take years?"

The fact that vaccines normally take up to 10 years to produce has had such an effect that some people don't trust the Covid vaccine because it has appeared so quickly, barely a year after the pandemic began. However, there are reasons for this. The first is to do with something that has happened in all sectors. Society has shown that is has been able to react on a large scale to new and unexpected changes. For instance, would we be able to work from home en masse to keep the cog wheels turning? We didn't know until we tried and found that we could. What has happened with the vaccines is quite similar: we have been able to produce these faster.

Emili Esteve, the technical manager of Farmaindustria, says that "never in history have so many people worked on something at the same time and so intensively". From need came cooperation. Rival companies have joined forces, and opposing fields like university and private research have shared their resources and talent. That meant the result was always going to be unconventional.

In this race, bureaucratic obstacles have also been eased. For example, regarding the time the authority responsible for guaranteeing the safety of the product, the European Medical Agency (EMA), takes to study and authorise a drug.

"In the best of cases, it normally takes a year after the tests have ended for a drug to be studied and authorised," says Esteve, but in this case the tests were completed and authorisation granted almost at the same time. How was that possible?

"By studying the scientific evolution of the vaccine at the same time as it was being developed. The EMA reviewed the documentation as it was produced, during each phase, instead of waiting for all of it at the end," he says. So the answer came immediately: when they had to give their decision, they had already done the work.

In addition, some logistical requirements had been set aside, such as labelling. Under normal circumstances it would be unthinkable for a product to come onto the Spanish market with a label in nothing but English, but making sure it could be ready in every EU language would need "a huge amount of effort" and would hold everything up.

The Pfizer laboratories, who have produced the vaccine developed by BioNtech and the first to receive EMA authorisation, make another important point: "We are investing at risk to do what is necessary to produce the highest possible number of doses as quickly as possible," they say. This has never been seen before: producing 'at risk'. They mean they are not waiting for official authorisation before starting to produce the vaccine. This has never happened with any drug before, but the medical emergency makes it necessary. What they are risking, though, is a financial loss, not the quality of the vaccine. Although they are working "at extraordinary speed", they are complying fully with "all normal regulatory and operational measures," says Pfizer.

"I don't want to be the first, they haven't tested it enough"

This speed has also applied to the clinical tests. Has the testing time been long enough, when it normally takes years?

All the experts we consulted said it has. They say it is "impossible" that an institution like the EMA would give the go-ahead for an unsafe vaccine.

"Nobody would approve it if it didn't meet the technical requirements," insists Federico Martinón Torres, the head of Pediatrics at the Santiago de Compostela hospital and a member of the WHO's vaccine advisory committee. "They aren't being any less vigilant. They have increased the number of tests carried out to provide safe and efficient data," he says.

By this, he means that whereas 200 people might normally take part in the three phases of testing over three years, for example, about 40,000 people have taken part in the tests for the Covid-19 vaccine over a few months. Would these changes in time and numbers affect anything? "No, it doesn't affect what is essential, which is the results," says Esteve.

For Martinón, "after giving the vaccine to this many people, and monitoring them for two months, we can strongly rule out any serious side effects, which is what could occur immediately and has to do with the body's immune system. There is an absolute guarantee of safety in the short term".

"What about side effects in the long term?"

With these samples, say the experts we asked, the only adverse effects which could be missed are those which are rare or highly improbable, affecting one person among many thousands after a time. For now, the side effects described as serious, occurring with a frequency equal to or greater than 2% of participants, have been fatigue (3.8%) and headache (2%) after the second dose, says Pfizer. But the participants will continue to be monitored for a further two years.

Federico Martinón Torres agrees: "Approval of drugs in emergency situations is also regulated and in this case there will be special monitoring," he says. What is common to all drugs is the so-called 'vigilance phase' which begins when the product reaches the general population.

"With the data we have," he says, "I don't believe we will see serious side effects, at least during the time the first people to have the vaccine are monitored". If after a time side effects do occur, there are resources to detect them and intervene. "Nothing we do is zero risk, but no other product is safer than the vaccines," he says.

He and Ángel Gil, who is an epidemiologist and professor at Rey Juan Carlos I university, recall an example of these control mechanisms working. Sometimes vaccines have been withdrawn because of serious side effects. That occurred with the vaccine for rotavirus. After being authorised for use in the USA, they saw an increased risk of intestinal intussusception (when one part of the intestine slides into another) in a percentage of breast-feeding mothers; this could be fatal if not dealt with immediately. The vaccine was withdrawn and the later tests were the biggest ever carried out.

"The vaccine was stopped for seven years, until it was made safer," says Gil. "When drugs come onto the market they are always monitored and any side effect would be detected in time".

"These techniques are new, why experiment with them at a time like this?"

These first two authorised anti-Covid vaccines use the 'messenger RNA' technique, but it is not correct to refer to it as experimental. With normal vaccines an infectious vector is injected so that the body develops antibodies, but with this ribonucleic acid technique the cell receives an 'instruction' from this RNA. "These are temporary orders, in this case, to synthesise a similar protein to a specific part of the coronavirus so the cellular machinery creates defences against it," explains Martinón.

It is true that no other vaccine on the market uses this technique, but it is not new. Research has also been carried out on it for other illnesses such as flu (that has been temporarily halted to give priority to Covid), and its use is being normalised in other medical treatments such as those against cancer. "It is a promising and relatively simple technology," says Martinón. Its main advantage is the ease of reformulating the RNA message if the virus mutates. "The production process is fast and efficient," says Pfizer.

"They work on genetic material, that's scary!"

"Maybe the population has more information than it can deal with and people get confused about the terms. We see that every day in our field. The messenger RNA is not DNA, which can be recoded and cause genetic changes," explains Ángel Gil. The messenger RNA is a molecule that takes an instruction to the cell and, once it has done that, it disappears. "It's extremely fragile," says Martinón. That's why it needs to be kept at such a low temperature, one of its disadvantages which needs work to improve it.

"What if I'm one of the five per cent for whom it doesn't work?"

Well, rather than fearing side effects, we should continue to be afraid of the coronavirus, so in the risk/benefit equation the balance lies in favour of the vaccine. If someone who has the vaccine finds themselves among the tiny percentage in whom it is not effective, it just means they will not be immunised. In fact, that is what is really unknown about this vaccine: how long will it protect the body against Covid? This is why the WHO says people should not drop their guard and stop taking precautions against the coronavirus, because the vaccine may mark the beginning of the end of the pandemic but it is not going to bring it to an end in the immediate future.

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