We all have been eagerly waiting to get the vaccine to end the mayhem created by the corona virus. We would all like to believe that vaccination is the only way to stop the disease from spreading. Is that completely true, though?
As per the experts, vaccination doesn't mean the end of the virus. Vaccination solely guards your body against the dangerous effects of the virus. The infection can occur at any time, vaccination just helps in warding off the serious issues that it might trigger. People who have been vaccinated also need to abide by all safety measures to prevent contracting the virus. These people can even transmit the virus to others.
What this means is that for a vaccination to declare that is works, all it has to do is to prevent you from getting a severe infection. It may not prevent you from actually getting the virus in the future, although there are ongoing studies to prove just that.
In the next few months, Pfizer and Moderna are expected to release data that should indicate how often vaccinated people become infected by the virus, even if they have no symptoms. The companies have been testing participants in their vaccine trials for antibodies to a protein called N that is part of the corona virus but not part of the vaccine. Finding those antibodies would mean that a vaccinated person has been infected by the virus.
So what exactly did they study when the made the vaccine?
The Pfizer and Moderna trials tracked only how many vaccinated people became sick with Covid-19. The study essentially took 2 groups and put them into a placebo group and a vaccine group and studied the risk of people getting sick with the corona virus without actually studying if the vaccine would prevent the infection in the first place.
Having said that, the vaccine will offer some protection from getting the virus. The way it works is this. The vaccine provokes the immune system of the receiver to make antibodies against the virus. Once the antibodies are formed, the immune system is primed to attack anything that remotely resembles the corona virus so that if you do get exposed and the virus does enter your system, it should be attacked by the antibodies.
How does this differ from immunity obtained after being infected?
In most respiratory infections, including the new corona virus, the nose is the main port of entry. The virus rapidly multiplies there, jolting the immune system to produce a type of antibodies that are specific to mucosa, the moist tissue lining the nose, mouth, lungs and stomach. If the same person is exposed to the virus a second time, those antibodies, as well as immune cells that remember the virus, rapidly shut down the virus in the nose itself before it gets a chance to take hold elsewhere in the body.
Vaccinated people may still harbour the virus in their nose and throat and these people who may not develop any symptoms could possibly be transmitting the virus without ever knowing it. It would only depend on whether the virus can replicate faster, or the immune system can control it faster.
What are breakthrough cases?
Breakthrough cases are those cases that test positive even after receiving the vaccine and can be either symptomatic or asymptomatic. This might occur in those people whose bodies cannot produce a robust reaction to a vaccine. Breakthrough infections are generally mild and do not require hospitalizations. Some people may have no symptoms at all and may be discovered only through testing. Absence of symptoms actually means that the vaccine is doing exactly what it is supposed to do: prevent people from getting sick, even if it does not fully block the virus from infecting them. If vaccinated people become silent spreaders of the virus, they may keep it circulating in their communities, putting unvaccinated people at risk.
Why are vaccinated people are testing positive for the virus?
- They are not following the precautionary measures such as wearing masks in public, sanitizing hands, maintaining social distancing and ignoring the other safety protocols as advised by the health ministry
- Not following the after vaccination rules as told by the doctors (eg alcohol consumption, taking immunosuppressive drugs)
- Not getting the second dose on time or not getting the second dose at all
- Barrier in immunity (may not mount a good enough immune response)
As of now, the only way to be absolutely sure of not getting the infection is to continue to follow strict hygiene measures in terms of hand washing and sanitizing, respiratory hygiene including wearing a mask at all times when outside your safe zone or in presence of strangers, covering your mouth and nose when your cough or sneeze, not rubbing your eyes, nose or mouth under any circumstances. These measures have to continue until a larger segment of the population is vaccinated and the transmission chain can be effectively broken.