QF infectious disease expert addresses COVID-19 vaccine concerns

As Qatar’s vaccination drive picks up pace and more and more people are vaccinated, there are some concerns amongst the public regarding how long vaccine-generated immunity will last.

Dr. Laith Abu-Raddad, Professor of Infectious Disease Epidemiology at Qatar Foundation partner university Weill Cornell Medicine-Qatar (WCM-Q), addresses these as well as some other post-vaccination concerns.

Q: Data suggests even after taking both doses of the vaccine, individuals could still contract COVID-19 and spread it to other people. So, why take the vaccine?
A: This is a bit like saying, why put on my seatbelt in the car when I can still get into an accident and possibly injure myself. The seat belt, in most cases, minimizes damage. It is the same with the vaccine. Yes, you are not 100 percent protected, but you are a lot more protected – up to 95 percent more than unvaccinated individuals. And even if you do catch COVID-19 after, the vaccination will prevent you from getting very sick or ending up in the hospital.

Being vaccinated will not just offer protection now, but also possibly in the future. Yes, it is possible that the efficacy of these vaccines against new variants could be lower but this is not necessarily the case for the severity of the infection. This basically means, even if in the future you get infected with a new variant, the severity of the infection will be low which is what ultimately matters. At the end of the day, it is okay to catch a cold which is likely what a new variant will cause in a vaccinated individual, but it's not okay to get to be in the ICU – as could be the case if not vaccinated.

Another thing to remember is, vaccinated individuals can still be asymptomatic carriers of COVID-19 and potentially spread it to others, which is why it's so important that those vaccinated continue to wear masks and practice all social distancing measures.


Q: Why does the second vaccine dose produce more side effects, such as fever or body ache?
A: This is the case for good reason! With the first dose, the most commonly reported side effect is soreness at the injection site. After the second dose, the side effects are more noticeable, as was my own experience too. They include a low-grade fever, shivering, mild fatigue, and body ache. These side effects typically resolve within 1 to 2 days, and are indicative of the vaccine activating the immune system.

The first dose basically nudges the immune system to inform it that there is a virus and that an immune response is needed. The first time around the antibody response is slow to build up. Think of it like this – with the first dose, the body starts to build the “factories” that will generate the antibodies to target this virus; this takes a couple of weeks. When the second dose is administered, the body already has the “factories” up and running but is awaiting a signal to start mass production of antibodies. The second dose is this signal. Once it’s administered, right away the body produces massive amounts of antibodies, mounting a very strong immune response which is why more symptoms appear after the second dose.

Q: How long are the vaccines effective for?
A: Frankly, it means very little at this stage. We do not know how long vaccine immunity will last, and to what degree these vaccines will be effective against future variants of the virus.

While we don’t have sufficient data on how long immunity from the vaccine will last, we can draw an analogy with natural immunity because we think it is similar to vaccine immunity. It is also possible that vaccine-derived immunity may be better and last longer than immunity derived from virus infection.

In Qatar, we have been following natural immunity developed by a cohort that previously contracted COVID-19. The cohort consists of over 40,000 people who have been followed for more than seven months now. We have not seen any waning of immunity in the cohort so far. This is encouraging and potentially means that the vaccines will be able to give us strong immunity against the virus, for I would say, a year if not more, provided we do not have new variants that may escape this immunity. As variants increase, we will need to have booster doses. Vaccine developers are already working on potential boosters for emerging variants of concern.

Q: If the virus keeps evolving, should I even consider taking the vaccine?
A: Absolutely! The vaccine is the best and only tool we have to stop the virus from evolving and leading to more mutant variants. It’s quite simple – the more the virus replicates, the more the chances of a mutant. The only way out of this vicious cycle is if more and more people get vaccinated, which in turn, would mean fewer opportunities for the virus to replicate and mutate.

This, of course, would require high vaccination rates across the world, and not just in some countries. The trouble is the vast majority of the global population has limited to no access to these vaccines. In countries that don’t yet have access to the vaccine, new variants will keep popping up, and sooner or later will spread to other countries. To stop the generation and spread of new variants, the vaccine uptake must be global.