What increases the risk of breakthrough infections?
We're all aware of the damage caused by the second wave of coronavirus. Now, amid fears of a possible third wave, experts believe following COVID-appropriate behaviour and getting oneself vaccinated should be prioritized at all costs.
But considering the fact that many fully vaccinated individuals are contracting the virus, people have started to doubt vaccine effectiveness and have become more hesitant. That said, researchers have been conducting studies to answer why such breakthrough cases are occurring on a regular basis.
It seems that a few things may in fact be increasing your chances of contracting the SARs-COV-2 virus, even when you've received both your vaccine doses.
What is a breakthrough infection? Symptoms to watch out for
A breakthrough infection occurs when a person contracts a virus even after being fully vaccinated against it. He or she either remains asymptomatic or develops mild to moderate symptoms, while some even may succumb to the virus, but it is believed to be a rare occurrence.
Additionally, the COVID symptoms experienced by a fully vaccinated person may be different from that of the original symptoms. According to the data from the ZOE COVID Symptom Study app, some of the symptoms of breakthrough infections are as follows.
- Headache
- Runny nose
- Sneezing
- Sore throat
- loss of smell and taste
Reports suggest runny nose was the second most commonly reported symptom in the app after headaches, which only makes it difficult to tell COVID symptoms apart from cold symptoms.
Since fully vaccinated people can still get infected, what increases their chances?
COVID-19 infection does not differentiate between people and can be contracted by anyone, adults and children alike.
Those who are fully vaccinated can also get the virus and develop symptoms. As per a study conducted by researchers from the United Kingdom, 0.2% of the population or one person in every 500 experiences a breakthrough infection once fully vaccinated. However, the research specifies that not everyone is at the same risk of contracting the virus. Certain factors can indicate who is more at risk or how well a vaccinated person is protected.
Variants can be a concerning factor
As we're all aware that the COVID vaccines were developed in respect to the original strain of the virus, it is possible that the current variants may evade the antibodies induced by the vaccines.
As per the data provided by The Public Health England, two doses of the Pfizer vaccine against the Alpha variant is less protected, lowering the risk of getting COVID-19 symptoms by 93 percent. In terms of Delta variant, the level of protection falls even further to 88 percent. Reports suggest that it works the same way for AstraZeneca vaccines too - which is India's Covishield vaccine.
This only indicates that the kind of variant that infects a fully vaccinated person determines how severe the infection is in him or her.
Read more: Coronavirus vaccination: Do recovered COVID-19 patients also need a booster shot?
Do vaccine types matter?
As much as variants increase your chance of getting a breakthrough infection, similarly, the type of vaccine you get also plays a significant role.
Clinical evidence has revealed that the Moderna COVID vaccine reduced the risk of coronavirus symptoms by 94 percent, whereas the Pfizer vaccine reduced this risk by 95 percent. Johnson & Johnson Janssen vaccine and AstraZeneca vaccines lower the risk only by about 66 percent and 70 percent respectively. However, it has been found that AstraZeneca (Covishield in India) may show higher efficacy if administered in long intervals.
So depending on which vaccine you get, your risk of developing a breakthrough infection may be influenced.
Does your immune system play a role?
When you get infected with the coronavirus infection, your body produces strong immune responses to fight the deadly pathogen. Even when you receive your COVID vaccine, it activates your immune system to produce virus-fighting antibodies. All these processes indicate that a person's immune system plays an important role in determining how well protected they are from infections.
That said, people who have a compromised immunity may be more prone to SARs-COV-2 infections, even when they're fully vaccinated.
This has also opened up discussions around the need for vaccine boosters, also known as the third COVID vaccine dose.
How long since you received your COVID-19 vaccine?
The fourth factor that could be influencing your level of protection against the virus, even after being vaccinated is the time duration since vaccination.
It is believed that vaccine-induced immunity can wane over time, which may be a reason behind the surge in breakthrough infections. Early researchers have found that the protection from the Pfizer vaccines may diminish over a period of six months after vaccination, which is surely alarming.
Although more research needs to be conducted to confirm whether or not vaccine-acquired immunity fades away over time, it is important to stay vigilant and get your booster shots as and when they're made publically available.