NOVEMBER 27 ― The Pfizer vaccine is touted to have a staggering 95 per cent efficacy. But according to the Wall Street Journal, recent unpublished data from Israel shows the Pfizer vaccine was only 40 per cent effective at reducing the risk of symptomatic Covid-19.

On November 23, the National Security Council posted on its Telegram channel a study by the Real-World Evaluation of Covid-19 Vaccines Under the Malaysia National Covid-19 Immunisation Programme (RECoVaM) and the National Medical Research Register (NMRR) which showed by September, those who were vaccinated in April to June had lower immunity compared to those who were vaccinated in July to August.

The study discovered in the case of Pfizer, its effectiveness was reduced from 89 per cent one to two months after vaccination, to 68 per cent three to five months later.

In light of the above, the relevant question to ask is if the original trial shows high efficacy (95 per cent), why did a large portion of people in the Israel and Malaysia studies get the virus?

To fathom this dichotomy of 95 per cent efficacy versus 40 per cent effectiveness (Israel) or 68 per cent effectiveness (Malaysia) shown by the Pfizer vaccine, there is a need to understand the difference between efficacy and effectiveness.

According to experts, vaccine efficacy refers to how well a vaccine performs under ideal, tightly controlled conditions like clinical trials. During trials for Covid-19, for instance, vaccines were given to people on a tight schedule.

Efficacy also has to do with what the researchers were studying. In the case of the Covid vaccines, they were looking at how well vaccines prevented symptomatic infection in a limited number of people, and NOT whether they prevented infection altogether or kept people from being contagious.

Bear in mind too, with Covid-19, it’s possible to be infected and not show symptoms, which means asymptomatic infection wasn’t covered by the researchers.

In the Pfizer study, the company tested about 44,000 people for symptomatic Covid-19 and only 170 developed the disease with at least one symptom. And of those, just eight had been vaccinated while 162 got a placebo. This is what added up to that 95 per cent efficacy rate.

This trial finding is to be read as follows: in a vaccinated population, 95 per cent fewer people will contract the disease when they come in contact with the virus and NOT that each individual is 95 per cent immune to the virus.

Vaccine effectiveness on the other hand refers to how well a vaccine works in the real world, outside of clinical settings. The real world is kind of messy in that not everybody gets their vaccines at the exact interval or that everybody has the same kind of immune system.

But as the vaccine was approaching the time for regulatory approval from the authorities, peoples’ behaviour started to change where in many places, businesses were open and large gatherings were happening again ― the reason why efficacy numbers in trials are often higher than the effectiveness we see in the real world.

And what makes it all the more complicated and unfathomable is the virus itself is still evolving via mutation in which the delta variant has become dominant in many countries and more transmissible than earlier strains of the virus.

It became dominant, months after the vaccines had been authorised and millions of doses have been distributed, which means our current shots were designed from an earlier version of the coronavirus.

Health officials expected breakthrough cases defined as fully vaccinated people contracting Covid-19 were more likely among people who had gotten the vaccine earlier on, in January or February. This is because antibodies the body produces after the vaccines to protect itself against the virus naturally decrease over time.

This and the unknown about variants is the big reason why the Biden Administration has announced a new vaccine recommendation of a booster shots programme for fully vaccinated adults 18 years and older in order to stay ahead of the virus.

What the programme is trying to achieve is to ensure immunity is kept high enough, hence increasing the chances the vaccine would prevent severe illness that could then lead to hospitalisation and deaths.

While breakthrough cases continue to occur, experts say these are usually mild and don't result in severe illness. And this is borne out by both the Israeli and Malaysian data showing the Pfizer vaccine has 91 per cent effectiveness against hospitalisation and death.

The Malaysian study also includes the vaccine Sinovac, which also exhibits the same pattern in terms of waning effectiveness through time.

All this points to the crucial need for booster jabs to forestall a new Covid wave and avoid a lockdown. Experts also recommend preventive measures like mask wearing and social distancing to keep the virus from spreading and mutating further.

It has since been proven by data worldwide that among Covid deaths, the majority comprises those who were not vaccinated and those with only one dose of vaccination, hence the endemic policy of relaxing restrictions only for those who were fully vaccinated.

With the number of severe Covid-19 cases among vaccinated people increasing in Malaysia, Health Minister Khairy Jamaluddin has called on all to take booster shots. ― Reuters pic
With the number of severe Covid-19 cases among vaccinated people increasing in Malaysia, Health Minister Khairy Jamaluddin has called on all to take booster shots. ― Reuters pic

With the number of severe Covid-19 cases among vaccinated people increasing in Malaysia, Health Minister Khairy Jamaluddin has called on all to take booster shots.

On the vaccine Sinovac, he said: “While Sinovac is effective, there is evidence its effectiveness wanes sooner. That's why we want you to take whatever booster is on offer,” Khairy tweeted on November 20.

He further explained the faster waning period is the reason why the interval for Sinovac booster shots is three months, compared with six months for Pfizer and AstraZeneca.

In recent days we have seen the latest wave of Covid-19 running berserk in Europe. Some countries have imposed partial lockdowns and placed more restrictions on unvaccinated people.

Germany, which has declared a state of emergency, broke a new record on November 18, reporting more than 65,000 new cases. In the Netherlands, more than 20,000 new cases were reported on November 17, a new record for the third day in a row, and on the same day in France, where a fifth wave of the pandemic is underway, the number of new cases topped 20,000, a level not reached since August 25, Reuters reported.

So it’s not paranoia when the authorities in Malaysia are warning about a new wave, and the best thing we as responsible citizens should do is to heed the advice to religiously observe the SOPs, especially going for a booster shot where the appointment date is given on the MySejahtera app.

It is indeed very assuring when on November 21, Khairy announced the Health Ministry will introduce a heightened alert system to detect early signs of an increase in Covid-19 cases. Through the system, the MoH proposed some sectors be tightened if there was an increase in cases, but it would not be a “total lockdown.”

“If we can, we want to avoid lockdown because lockdown not only disrupts the economy, but has other effects on family well-being and mental health,” said Khairy.

He also reminded the public not to be too complacent when the states transitioned to Phase Four of the National Recovery Plan. “We are very worried because we have seen the early signs (of rise in cases). However, it has not reached the level of paralysing the health system, but the signs are very clear,” he added.

Last week Austria became the first European country to make Covid-19 vaccination a legal requirement, with the law due to take effect in February.

Politicians in neighbouring Germany are debating similar measures as intensive care units there fill up and case numbers hit fresh records.

* Jamari Mohtar is the Editor of Let’s Talk! an e-newsletter on current affairs.

** This is the personal opinion of the writer or organisation and does not necessarily represent the views of Malay Mail.