Although Covid vaccinations have shown to be effective in clinical studies and real-world data, some patients are still getting an infection with SARS-CoV-2 after immunization. A runny nose, headache, sneezing, a sore throat, and a loss of smell are the five most typical signs of breakthrough infection.
The safety effects of vaccination will be at their peak two weeks after you receive your second dose of the vaccine. Although the chances of getting the virus are extremely slim at this time, it is still conceivable.
A breakthrough infection occurs when you acquire COVID after being wholly vaccinated. Experts say breakthrough infections are comparable to ordinary COVID-19 conditions, primarily detected in patients who have not even gotten their first jab. There are, however, some distinctions worth noting.
COVID Breakthrough Infections: Common Symptoms
Some symptoms are similar to those experienced by patients who have not received a vaccination. A headache, a sore throat, loss of smell, a runny nose, sneezing are the five most prevalent symptoms of a breakthrough infection, according to the COVID Symptom Study.
Fever and a prolonged cough are the two other most pervasive symptoms among the unvaccinated. Once you’ve had your COVID-19 jabs, these two “typical” COVID-19 symptoms become far less common.
According to one study, compared to uninfected people, people with breakthrough infections are 58 per cent less likely to have a fever. Even if fully vaccinated, a tiny percentage of the population will become infected with COVID-19 if exposed to the virus. It is more likely to occur in people over the age of 65 or who have significant medical concerns on the horizon.
In England, studies are being conducted. It has been discovered that when fully vaccinated, 0.2 per cent of the population, or 1 in 500, will experience a breakthrough infection. However, not everyone is at the same level of risk. Four factors appear to influence how well you are protected by vaccination.
Type of vaccine
The first is the type of vaccine you received and the relative risk reduction that each type provides. Relative risk reduction measures how much a vaccine reduces the risk of developing COVID-19 compared to not being vaccinated.
In clinical trials, the Moderna vaccine reduced the risk of developing symptomatic COVID-19 by 94%, while the Pfizer vaccine reduced the risk by 95%. AstraZeneca and Johnson & Johnson vaccines performed less well, reducing this risk by approximately 66% and 70%, respectively (though protection offered by the AstraZeneca vaccine appeared to rise to 81 per cent if a longer gap was left between doses)
Time from vaccination
However, these figures do not provide a complete picture. It is becoming clear that the length of time since vaccination is also important, which is why the debate over booster immunizations is heating up.
Early research, which is still in the preprint (and thus has yet to be reviewed by other scientists), suggests that the Pfizer vaccine’s protection waned six months after vaccination. Another preprint from Israel suggests the same thing. It is too early to tell what happens to vaccine efficacy after six months in the double-vaccinated, but it is likely to decline further.
Covid variant type
Another critical factor is the virus variant you have an infection of Covid. The risk mentioned above reductions were calculated primarily by testing vaccines against the original form of the coronavirus.
However, when suffering from the alpha variant, data from Public Health England suggest that two doses of the Pfizer vaccine are slightly less protective, reducing the risk of COVID-19 symptoms by 93 per cent. The level of protection against delta drops even lower, to 88 per cent, which also affects the AstraZeneca vaccine.
All of this is supported by the COVID Symptom Study. Its data suggests that in the two to four weeks following your second Pfizer jab, you are approximately 87 per cent less likely to experience COVID-19 symptoms when exposed to the delta. After a few months, that figure drops to 77%.
Immunity of the individual
It is critical to remember that the figures above refer to average risk reduction across a population. Your risk will be determined by your level of immunity and other individual factors (such as how exposed you are to the virus, which your job might evaluate).
Long-term medical conditions can also impair our immune system’s response to vaccination. Immune fitness usually declines with age. As a result, older people or those with compromised immune systems may have lower levels of vaccine-induced protection against COVID-19, or their protection may wane more quickly.
It’s also worth noting that the most clinically vulnerable people received their vaccines first, possibly more than eight months ago, which may increase their risk of a breakthrough infection due to waning protection.
