Received your coronavirus vaccination booster dose? Maybe you are even wondering if you need it? In this article, allow us to shed some light on the third Covid-19 vaccine booster shot.
Let’s look at why a booster dose is recommended by government authorities and the medical industry. Let’s also discuss the effects of mixing vaccines and the countries that are starting to require travellers to get their booster shots to enter and/or visit public spaces.
How does your vaccination booster dose affect your travel plans?
What are booster shots?
What are booster shots?A booster shot is meant to increase levels of immune responses. Simply put, a booster tricks the immune system into thinking that it is again seeing a pathogen. Once it does, antibody-producing cells, and other immune cells, go into action to protect you.
Why are booster shots recommended?
The SARS-CoV-2 virus has mutated over time. The fast-spreading variant known as Omicron has mutations on its spike protein. This allows it to better evade detection by our immune systems. In the past year, the emergence of new variants — Delta and Omicron — have made it much more difficult for our bodies to recognise the virus even if we are vaccinated.
You may be wondering if Covid-19 vaccination is effective if booster shots are recommended. One way to answer this question is to consider the vaccine’s efficacy in preventing severe infection and death and in stopping transmission and/or acquisition of this virus.
Studies have found that two doses of the AstraZeneca and Pfizer vaccines provide 79% and 90% protection respectively against hospitalisation and death. However, vaccines are not as effective in preventing the transmission and acquisition of this virus. Booster shots aim to plug this gap.
Should you mix vaccines?
Recent news headlines say heterologous boosting, i.e., the “mix and match” approach with coronavirus vaccines is highly effective and significantly strengthens immunity. Most reports quote the European Medicines Agency, which stated that in terms of immune responses, a heterologous booster approach appears to be as good as or better than a homologous booster approach (the same vaccine type is used as the booster).
A study published in the New England Journal of Medicine compared those in Israel who received 2 doses of the Pfizer-BioNTech Covid-19 vaccine with those who received the 2 doses plus the same vaccine as a booster.
Results found that those in the boosted group were 11.3 times less likely to get infected with the Covid-19 coronavirus and 19.5 times less likely to have severe Covid-19 than those in the un-boosted group.
Pharmaceutical giants, Pfizer and Moderna, have also announced that preliminary data suggest that three doses of their vaccines seem to offer good protection against the Omicron. Of course, their findings must be taken with a grain of salt since these companies produce these vaccines. There is a vested interest in producing favourable results and good reviews.
Malaysian researchers, the US FDA and CDC currently support heterologous boosting, i.e., the “mix-and-match” approach that allows people to choose a different vaccine for their booster than the one they started with. Do note that it is difficult to compare the performance of boosters as all of us have different antibody levels at the start.
Now, let’s look at the latest research.
All boosters increase antibodieS
In December, a report by the UK Health Security Agency suggested that people “who have had two doses of the Oxford/AstraZeneca jab 25 or more weeks ago have far lower protection against symptomatic infection with Omicron than with Delta.”
The Lancet (a weekly peer-reviewed general medical journal. A trusted source of information in the medical industry) published an article that found a 25-fold increase in antibodies for those that received two doses of AstraZeneca vaccine then a Pfizer booster.
This article is based on a study of almost 3,000 people who received a booster dose two to three months after their vaccination. It found that for those who received a Moderna booster (following AstraZeneca), antibody levels increased 32-fold.
Among those who had Pfizer for their first two shots, a third Pfizer dose saw antibody levels rise more than eightfold.
What about a Sinovac Booster?
In the Brazilian government-funded study, researchers from Brazil and Oxford University found those fully vaccinated with the Chinese-made Sinovac vaccine were shown to develop a high degree of immunity after receiving booster doses of either Sinovac, AstraZeneca, Pfizer or Johnson & Johnson vaccines.
Although a Sinovac booster also increased antibodies, results were better when a different vaccine was used, according to this study that included 1,240 volunteers from Sao Paulo and Salvador.
What if you have received Sinovac vaccination and a Sinovac booster? Preliminary results of a study conducted by the Pontifical Catholic University in Chile showed that the-19 Sinovac booster dose could activate cellular immunity against the Omicron variant. This study was done on individuals that received two doses of the same vaccine previously. The study found those who have received the Sinovac booster dose had T cell levels that are activated against the Omicron variant in a similar way to the original virus.
KKM’s guidelines for booster shots
On Tuesday (11 January 2022), Malaysia’s Ministry of Health (KKM) published frequently asked questions (FAQs) about Covid-19 booster shots. The FAQ stated that the duration of reception of a booster varies based on the type of complete vaccine that has been accepted. KKM’s guidelines are as follows:
- Individuals who are vaccinated with Comirnaty (Pfizer), are required to get a booster (Comirnaty [Pfizer] or AstraZeneca), three months after their second dose.
- Individuals who are vaccinated with AstraZeneca, are required to get a booster (Comirnaty [Pfizer] or AstraZeneca), three months after their second dose.
- Individuals who are vaccinated with Coronavac (Sinovac), are required to get a booster (Comirnaty [Pfizer], AstraZeneca, or Coronavac [Sinovac]), three months after their second dose.
- Individuals who are vaccinated with Covilo (Sinopharm), are required to get a booster (Comirnaty [Pfizer] or AstraZeneca), three months after their second dose.
- Individuals who are vaccinated with Spikevax (Moderna), are required to get a booster (Comirnaty [Pfizer] or AstraZeneca), three months after their second dose.
- Individuals who are vaccinated with Sputnik V, are required to get a booster (Comirnaty [Pfizer] or AstraZeneca), three months after their second dose.
- Individuals who are vaccinated with Convidecia (CanSino), are required to get a booster (Comirnaty [Pfizer] or AstraZeneca), three months after their first dose.
- Individuals who are vaccinated with Janssen (Johnson & Johnson), are required to get a booster (Comirnaty [Pfizer] or AstraZeneca), two months after their first dose.
more booster shots?
Israel and several European countries have begun to roll out fourth vaccine doses in response to concerns about waning immunity. Unfortunately, the coronavirus has a remarkable capacity for shape-shifting and mutation and some health experts are talking about the need for periodic boosters for the next few years.
KKM is noncommittal at this point. Its FAQ says:
Q: How long is the period of protection provided by the Covid-19 booster?
The duration of protection afforded by the booster cannot be determined at present because the evidence and information is still insufficient.
Q: What is the frequency of receiving the Covid-19 booster?
Based on the latest information, one dose of the booster is sufficient.
This means that at this point, it is still uncertain if more booster shots will be required in the coming months/years.
Countries mandating booster shots
Some countries have imposed an expiry date on the validity of a Covid-19 vaccine while others are looking specifically if booster shots have been received. For the former, if your vaccination is considered ‘expired’, you will not enjoy relaxed testing and quarantine measures available to fully vaccinated travellers.
France
As of January 24, if you are aged 16 or older; a tourist, and fully vaccinated against Covid-19 and more than seven months have passed from your final dose; then you will need to also get a booster shot to get a vaccine pass (which is needed for travellers to enter the country).
Furthermore, new requirements may be implemented in France on February 14. It appears that you will need a booster dose if four months have passed since your final dose. Authorities have yet to clarify if you need to be boosted within four months of travel or if a booster is required after those initial four months.
Greece
Greece has also increased Covid-19 restrictions and made vaccine passports mandatory for indoor spaces such as restaurants, bars, and cafes.
Anyone over the age of 60, including tourists, will now be required to get their booster shot else they will not qualify for the vaccine passport. The Greek Prime Minister is also asking the EU to ensure that the booster shots are made mandatory if travellers want to use the EU’s digital health pass in the future.
Abu Dhabi
Abu Dhabi is requiring people entering the city to show proof of booster shots. Visitors are no longer considered fully vaccinated unless they have received a booster at least six months after their second dose. Those wishing to enter Abu Dhabi must also have tested negative for the virus within the last two weeks.
Kuwait
Kuwait has made the booster dose mandatory for travellers wanting to enter the country. Authorities say that a booster shot must be received within after nine months of vaccine to be considered fully vaccinated. Travellers wishing to enter the gulf nation will also need to show their negative PCR test report not older than 48 hours on arrival.
Saudi Arabia
Saudi Arabia is requiring vaccine boosters for entry into public places beginning February 1. This applies to those aged 18 and over who have received their second vaccine dose at least eight months ago.
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