Coronavirus: Why are breakthrough COVID-19 infections rising post the Delta variant? What does it mean?

With a sharp rise in overall coronavirus vaccination figures worldwide, there has also been a rise in people still testing positive for coronavirus infection, despite being fully vaccinated. Breakthrough infections, as they are medically termed to be are intriguing, as well as making many wonder about the workability of coronavirus vaccines.

However, as experts say, breakthrough COVID infections are nothing uncommon, and as we begin to see more variants emerge, the number of such cases shall rise up too.

Should we then, really be worried about our post-vaccination life? How risky are breakthrough infections? Here's what we know so far

A breakthrough COVID case is termed as a positive coronavirus diagnosis in a person who has been fully immunized (i.e., received two entire doses and has peak immunity). According to experts, a breakthrough COVID case will be characterized as such if a person records symptoms or some level of complications upon exposure.

While it is presumed that most vaccinated people develop fewer complications or risks with COVID infection, there is still an established risk of catching the infection.

Breakthrough cases are also seldom reported with other vaccines. However, while the COVID-19 vaccine is still experimentally built, the risk of getting sick with other vaccines is on the lower end, since they have been used for long and underwent a lot of development.

Scientifically, the statistical figures of developing an infection upon vaccination remain low and deemed 'rare'.

However, as with the COVID-19 vaccine, there's more than one reason which is likely to increase one's risk of getting infected despite being fully vaccinated.

For one, the approved vaccines we have with us right now are proven to minimize the risk of severity, transmission and death- but not fully cut down the risk of the infection itself. Hence, even after vaccination, there's some degree of presumed risk which puts one at risk.

The risk of developing a breakthrough infection also goes up if you haven't yet developed peak immunity. Since antibodies build up 10-14 days after, a person carries the potential risk of infection for at least 2 weeks post infection. The risk of infection goes significantly up in the weeks before the second vaccination.

Scientists also believe that the higher the vaccinated population, the more will we see the number of breakthrough infections. This is also the case with countries like Israel and the United States of America, wherein a lot of positive cases are seen amongst the vaccinated crowds.

While cases are expected to rise further, a lot of it has to do with the current variants which are propping up. Variants of the SARS-COV-2 virus, which carry properties that surpass antibodies and cause infection can also render some (or full) vaccine-driven antibodies ineffective.

Cases of variant-driven surge have also been reported in areas with low-vaccination coverage. Variants are also speculated to rise up if vaccination rates aren't paced and we don't achieve herd immunity. So, as long as vaccination rates remain low, and variants continue to spread, there will be a risk of breakthrough COVID cases, even if low. Variants of coronavirus, thus, not just put an unvaccinated person at risk of severity, but also pose a risk for someone who has been vaccinated.

Currently, most cases of breakthrough infections have been reported in countries wherein the Delta and Lambda variants of coronavirus, both linked to severity and antibody-lowering capabilities have been detected. Researchers have observed that in comparison to the Alpha variant of the virus, the Delta variant is 60% more transmissible and causes severe symptoms. It was also the driving factor behind India's devastating caseloads seen during the second wave. The Delta variant of coronavirus is currently also the most dominantly spreading strain of COVID-19 and has been categorized as a Variant of Concern (VoC).

The variant-linked havoc will only be controlled if the pace of vaccination is fastened. Once more people are fully vaccinated, it'll help reduce the spread of COVID-19 throughout the world because the virus won't be able to infect as many people.

While there's still a sizeable risk of infection post-vaccination, experts are currently advising to not judge the efficacy of vaccines just as yet.

Evident case studies and clinical research has highlighted that after being fully vaccinated, one's risk of contracting COVID-19 goes down, the risk of transmission and spread too lowers. Even for those who do, unfortunately, catch the infection, vaccines have been proven to help.

It has been seen that the infections amongst those who are vaccinated tend to be on the milder side- some can have asymptomatic infections, or record less than 5 symptoms. The risk of severity, hospitalization also goes down, almost with all vaccines and was also seen during the second wave of COVID-19 in India.

Apart from that, vaccine driven immunity is also capable of hastening recovery timelines as vaccinated people with breakthrough infections tend to recover faster than unvaccinated people.

The concept of booster, additional COVID-19 vaccine shots have been discussed of late. Different booster shots have been shown to strengthen immune defence and give long-lasting immunity, which may also protect against any variants of concern, such as the Delta variant.

While some say a booster shot may become a necessity in the future, and proven to be quite efficacious, there's no clarity on the same whether we need booster doses as of right now. Experts are continuing to study the power of vaccines, and even if the time does come when booster shots are available, the prioritization of the same may be done for those who are vulnerable to severe risks or have a dysfunctional immune system which could reduce protection promised by prior vaccine doses.

If you have been vaccinated, do remember that while you are certainly protected to a level, and there's a low established risk of breakthrough infections (even if more cases are recorded globally), it's quite crucial you keep the masks on. Masks are the first form of defence and protect one against a lot of risk factors in a mixed population, where we have a lot of vaccinated and unvaccinated people. Wearing masks diligently is also the current advisory issued in countries where variants are adding cases.

Apart from this, there are also some additional preventive measures vaccinated people can take to further safeguard themselves:

-Socially distance yourself from the ones who have not been vaccinated

-Avoid unnecessary exposure in high-risk/populated places right now.

-Reduce the risk of airborne transmission by following rules of proper ventilation. Do not have big gatherings indoors or in closed spaces.

-Continue to wash and sanitize hands frequently.

-Get a test done if you start to experience any symptoms.