The end of the corona pandemic is in sight, the World Health Organization reported last week. Never before since the outbreak began in 2020 has WHO leader Tedros Adhanom Ghebreyesus been so optimistic. But we are not there yet, he emphasized. The virus is not gone, countries must continue to fight it and be prepared for new upheavals. In India, for example, the Omikron subvariant B2.75 is gaining ground.
In the Netherlands, the first people can therefore get a repeat shot from Monday at the GGDs with the recently approved renewed corona vaccines. They protect better against the Omikron variant. What has been updated in these vaccines and for whom is a repeat shot useful? Four questions about the new vaccines.
1 Who can get the repeat shot?
First of all, the elderly and vulnerable – for them it will be the fifth shot. In the coming weeks, all people over 60 will receive an invitation, and healthcare staff with patient contact. From the beginning of October, GPs will invite people under 60 who are at increased risk of severe Covid-19. After that, anyone from the age of 12 who wants to can get a shot – for everyone under the age of 60, this is the fourth shot that is offered. There must be at least three months between the last vaccination or corona infection and the repeat shot, for a better booster effect.
2 What is in the modified vaccines?
Both producer Moderna and Pfizer/BioNTech have adapted their existing vaccines in such a way that they generate a better immune response against Omikron, the coronavirus variant that now causes almost all infections. Omikron is much more contagious and highly modified compared to the original virus from Wuhan, on which the existing vaccines are based. As a result, they protect less well than at the start of the pandemic.
The new vaccines are so-called bivalent vaccines. They contain pieces of genetic code (mRNA) of the spike protein of the original virus strain, as well as of the Omikron subvariant BA.1 or of the subvariant BA.4 and BA.5 (which have identical spike proteins). That is not uncommon, flu vaccines often contain material from four different virus variants. In total, it contains as much mRNA as in the original vaccines. Otherwise they are identical to the original vaccines.
In the Netherlands, almost all corona infections are now with the BA.5 subvariant, but the renewed vaccines against that subvariant have not yet been delivered, only those with BA.1. Both the bivalent vaccines against BA.1 and those against BA.4-5 are used, a spokesperson for the RIVM said. “No difference in efficacy has been reported between the two, and we want to start vaccinating as soon as possible, so we’re starting with what’s there now. We expect an improvement in the immune system from all these vaccines.”
3 Why is a repeat shot necessary?
Antibodies that you make after an infection or vaccination disappear from the blood over time. After a repeat injection, the first line of defense, the antibodies, is increased again for a longer period of time. The more antibodies, the faster you can clear the virus after an infection. In addition, the second line, the memory cells and other cellular defenses, become stronger again. It is especially important for protection against serious illness. The renewed vaccines strengthen both lines of defense against Omikron.
“You not only get more different antibodies and immune cells, but the quality also improves,” says vaccinologist Cécile van Els of Utrecht University and RIVM. “It is expected that this will also align better with possible new variants.” The side effects of the vaccination are similar to those of previous vaccines, and are usually short-term.
It is beneficial for society if the entire population’s defenses are as good as possible. This makes it less easy for the virus to spread, and fewer people get sick. This also limits absenteeism in an already tight labor market. Van Els: “You lift an entire country over the winter with it.”
4 What considerations are there in whether or not to take the shot?
For the elderly and for people with a weak immune system, it is wise to refresh the immune system, because they are more likely to have a serious course of the disease. Those who live or work with vulnerable people can also limit the risk of infecting others with a repeat injection.
Other people can consider how much immunity they’ve built up, whether they’re dreading getting Covid-19 or long-term Covid, and what their previous experience with the vaccine was. Anyone who is healthy and has already had two or three shots, and who also had Covid-19 this year, probably still have sufficient immunity. “After only three shots, you are still well protected against serious illness, but slightly less against illness from Omikron. The repeat shot not only boosts that protection against serious Covid-19, but also that against infection, mild illness, and a little against passing on the virus,” says Van Els. Therefore, a repeat shot is still helpful for most people.
Those who suffered a lot from side effects after the previous vaccinations may prefer to ignore them. Van Els recommends that you consult your GP. People who prefer not to get a vaccine from Pfizer or Moderna, but who do want to boost their immunity, can get the vaccine from Janssen, a spokesperson for the RIVM said. Other vaccines are not currently approved for use as boosters.
People who are in doubt can discuss their questions with an expert, such as the general practitioner, or with someone from the Doubt Phone.