To get or not to get – that’s the Covid-19 booster shot question

 

Health minister Khairy Jamaluddin is urging Malaysians to get Covid-19 booster shots because the effectiveness of the vaccines wanes over time.

On Nov 21, he said the Sinovac vaccine was the quickest to lose its effectiveness, adding that most of the seriously ill patients warded in intensive care units were Sinovac recipients.

On Nov 10, Khairy revealed that about 40% of people did not turn up for vaccine booster shots on their appointment dates under the National Covid-19 Immunisation Programme.

“If booster take-up is low, especially among the elderly and those with comorbidities, hospitalisation numbers will go up,” he tweeted.

In Malaysia, the health authorities began offering booster shots from Oct 13 for those who were fully vaccinated.

In fact, health authorities in many countries are urging their people to go for booster shots to protect themselves.

On Nov 23, for instance, the World Health Organization’s European office urged the countries in the region to offer booster shots to those vulnerable to Covid-19.

Israel was one of the first countries to offer booster shots to their citizens. Its health officials say booster shots have helped reduce the impact of the fourth wave of the disease.

Many Malaysians who have already received two doses of vaccine are uncertain as to whether they should get booster shots. A few of my friends have already got theirs, but others say they do not plan to do so.

Do we really need a booster shot? There seems to be no clarity on this from scientists and medical specialists.

In September, the New England Journal of Medicine published three studies, including one by the Weizmann Institute of Science in Rehovot, Israel, which showed that a booster dose substantially reduced Covid-19 cases and severe illness.

The Israeli study showed that 12 days after getting a third dose, the SARS-CoV-2 virus infection rate was 11.3 times lower in the booster group than in the control group.

The Center for Infectious Disease Research and Policy at the University of Minnesota reported in September that several new studies on the Pfizer/BioNTech mRNA Covid-19 vaccine “describe good effectiveness against the Delta (B1617.2) variant after a booster dose and high but waning protection against infection and severe illness six months after the second dose”.

The researchers said: “Our findings give clear indications of the effectiveness of a booster dose even against the currently dominant delta variant. Future studies will help determine the long-term effectiveness of the booster dose against current and emerging variants.”

However, a leading scientist behind the AstraZeneca vaccine, Oxford University professor Sarah Gilbert told The Telegraph in October that not everyone needed booster shots.

She was quoted as saying: “We will look at each situation; the immuno-compromised and elderly will receive boosters. But I don’t think we need to boost everybody. Immunity is lasting well in the majority of people.”

Meanwhile, Yale Medicine infectious disease specialist Dr Albert Shaw said: “The main question is how long the immunologic protection against SARS-CoV-2, which causes Covid-19, lasts. And since we are learning about Covid-19 in real time, this is hard to know definitively.”

He adds: “You can certainly look at antibody levels, and that does offer some indication of how much protection lasts. But even if they have waned, that doesn’t necessarily mean the body’s capacity to respond to exposure is gone.

“One of the most amazing parts of the immune system is immunologic memory of past infections or vaccines. If you are re-exposed to something (via a booster shot, that follows the original exposure by vaccination), the memory response is even more vigorous than the original. This memory response includes antibody responses, but also includes an additional arm of the immune system controlled by a different group of white blood cells called T cells or T lymphocytes.”

T cell responses, he said, might prove to be just as important as antibody responses in protecting against infection or against serious disease requiring hospitalisation.

Indian Council of Medical Research (ICMR) director-general Dr Balram Bhargava said on Nov 22 that there was no scientific evidence so far to support the need for a booster vaccine dose. India’s priority “right now”, he said, was to ensure everyone had two doses of the vaccine.

In September, he was quoted by Indian media as saying: “We have had some studies in India, including Bangalore, where some hospitals looked at the antibodies and found that 95% antibodies persist for more than a year. Therefore, the talk of booster is not pertinent.”

On Oct 21, it was reported that India had administered 1 billion doses of vaccine.

In pushing for US Food and Drugs Administration approval in July for a booster shot in adults, Pfizer’s Dr Mikael Dolsten was reported as saying early studies showed that a booster shot could significantly increase a person’s antibody levels.

However, CBS quoted Tufts Medical Center epidemiologist Shira Doron as saying: “But antibody levels are not clinical trial data and they are not efficacy data. And we do not have the evidence right now to tell us that we need third shots.”

It also quoted Dr Mark Siedner of Massachusetts General Hospital as saying: “Getting a third shot increases your antibody levels. That is reassuring. But you don’t necessarily need higher antibody levels to protect yourself from this disease.”

On Oct 4, WHO, in what it termed an “interim” statement, said: “The rationale for implementing booster doses should be guided by evidence on waning vaccine effectiveness, in particular a decline in protection against severe disease in the general population and in high-risk populations, or due to a circulating VoC (variants of concern). To date, the evidence remains limited and still inconclusive on any widespread need for booster doses following a primary vaccination series.”

The question is what happens after the effect of the booster shot wanes in six months or a year or so. Does it mean we will have to continue taking booster shots forever?

The US’ Centers for Disease Control and Prevention director Dr Rochelle Walensky told CBS News in August that she did not think a yearly Covid-19 booster would be needed.

“It does look like after this third dose you get a really robust response. This virus has been humbling, so I don’t want to say never, but we are not necessarily anticipating that you will need this annually.”

However, Pfizer CEO Albert Bourla told Business Insider, also in August: “The most likely scenario is we will be needing annual re-vaccination, as we do with the flu vaccine.”

And what has Dr Anthony Fauci, the US’s top infectious disease expert, got to say about whether there will be a need for a fourth or more booster shots?

“The honest answer is that we do not know at this point, but we’re collecting data. We may not need to get boosted every six months or so but if we do, we’ll address it. We’ll find the data, make it public and address it accordingly,” Fauci said at a White House briefing on Nov 22.

Truth is, uncertainties about the disease persist even after almost two years. No one can say with certainty, for instance, if the disease will taper off or whether more variants will arise.

No one can say if we will ever be able to find treatment more effective than the vaccines, or if we’ll have medicines without side effects.

One wonder’s what a full study five or 10 years from now will reveal about the disease, the vaccines and the way governments handled the pandemic.

Will new medical conditions or diseases 10 years from now be attributed to medication or vaccines taken for Covid-19? - FMT

The views expressed are those of the writer and do not necessarily reflect those of MMKtT.