New Delhi: Did you know two weeks after your second jab the protective effects of vaccination will be at their highest? At this point, if you get an infection even when you are fully vaccinated, then it’s referred to as a “breakthrough” infection, according to a new study.
Breakthrough infections are similar to regular Covid-19 infections in unvaccinated people but can exhibit different symptoms, as per the PTI report. Here is what to look out for if you’ve had both jabs. According to the Covid Symptom Study, the five most common symptoms of a breakthrough infection are a headache, a runny nose, sneezing, a sore throat, and loss of smell.
These symptoms are similar to people who haven’t had a vaccine experience. If you haven’t been vaccinated, three of the most common symptoms include headache, sore throat, and runny nose. However, the two other most common symptoms in the unvaccinated are fever and a persistent cough.
In the UK, research has found that 0.2 percent of the population – or one person in every 500 – experiences a breakthrough infection once fully vaccinated. But not everyone is at the same risk, the agency said citing the study. Four things appear to contribute to how well you are protected by vaccination.
What are factors raising the risk of vaccinated people getting Covid-19?
Vaccine type
It depends on the specific vaccine type you received and the relative risk reduction that each type offers. Relative risk reduction is a measure of how much a vaccine reduces the risk of someone developing Covid-19 compared to someone who didn’t get vaccinated.
If you go by the clinical trials, then the Moderna vaccine reduced a person’s risk of developing symptomatic Covid-19 by 94 percent, while the Pfizer vaccine reduced this risk by 95 percent. The Johnson & Johnson and AstraZeneca vaccines performed less well, reducing this risk by about 66 percent and 70 percent respectively (though protection offered by the AstraZeneca vaccine appeared to rise to 81 percent if a longer gap was left between doses).
Time since vaccinated
The above figures may not give a complete picture. The chances of getting infected also depend on the length of time since being vaccinated. It is why the chatter over booster immunisations is growing in intensity.
Virus Variants
It also depends on the variant of the virus. The reductions in risk above were largely based on testing vaccines against the original form of the coronavirus.
But when facing the alpha variant, data from Public Health England suggests that two doses of the Pfizer vaccine are slightly less protective, reducing the risk of getting symptoms by 93 percent. Against delta, the level of protection falls even further, to 88 percent, as per the study. The AstraZeneca vaccine is also affected this way.
Immune system
Most importantly, remember that the above figures refer to average risk reduction across a population. However, your own risk will depend on levels of immunity and other -specific factors (such as how exposed you are to the virus, which might be determined by your job).
Immune fitness typically reduces with age. Long-term medical conditions may also impair our response to vaccination. Older people or people with compromised immune systems may therefore have lower levels of vaccine-induced protection against Covid-19 or may see their protection wane more quickly.