I had my first and second dose of vaccine at St. Mary’s Hospital in London. Each dose is nearly 2 months apart and I am happy that I didn’t have any extreme reaction from it. Right after the vaccination, I felt feverish and tired. I had body pains especially on the injection site but it was relieved by paracetamol.
Now that I am vaccinated, am I 100% safe from the virus?
Technically, most of the literature I read on the internet is that we are safe 2 weeks after receiving the final dose regardless of what vaccine we had but we still have to take precautions because there are other covid-19 variants that potentially make us vulnerable to acquire infection.
Why do we have to wait 2 weeks? How does the vaccination work? What happens to our body?
Traditionally, vaccination works because it stimulates the immune system to produce antibodies against the virus. White blood cells such as the Macrophage, T-Lymphocytes and B-Lymphocytes serve as soldiers of our body in creating weapons against an infection.
Basically, the macrophage eats an invasive microorganism and leaves behind antigens. These antigens are recognised by B-Lymphocyte cells and the T-lymphocytes cells as “dangerous”. Because of that, B-cells (plasma cells) will produce antibodies, which prevent the spread of the viral infection. On the other hand, the T-lymphocytes can stimulate the inflammatory response of the body and will become killers of the infected cells in the body. This process takes time and experts says that it takes 2 weeks for the covid19 to fully take effect.
Usually, developed vaccines use weakened viruses or part of an antigen to create a defensive immune response to diseases. We have seen these work on infectious diseases such polio, measles and Hepatits B.
In my case, I had the Pfizer/ BioNtech vaccine, which uses mRNA method to inoculate our body. RNA (Ribonucleic Acid) is a single strand DNA, which helps in converting information in our DNA into proteins and it carries (a message) genetic codes of viruses.

This year, scientists introduced the mRNA vaccine as a breakthrough method of vaccination. The messenger RNA (mRNA) vaccine uses a strand of RNA packaged in a lipid nanoparticles (tiny fat droplet) that helps in delivering the “message” inside a human cell. These cells will create spike proteins similar to the corona virus and eventually multiply. From there, the T cells will recognise this as a threat and generates immune response.
As I’ve mentioned earlier, I only had a headache, a low grade fever and body pains after the vaccination. It is nothing to worry about because these symptoms are expected. My wife and some of our friends who had the vaccine felt the same.
There are a lot of vaccines developed for covid-19. In comparison, Moderna and Pfizer/ BioNtech used the mRNA method but the Johnson and Johnson’s Janssens as well as the Oxford-Astrazeneca used the viral vector approach, which uses a similar virus with a covid 19 genetic code and introduce it to the human body to stimulate an immune response. Sinovac, on the other hand, uses inactivitated corona virus to build Covid-19 protection.
I understand that there are a lot of debates regarding the efficacy, safety, cost, kickback of the government (allegedly) and what nots regarding the vaccines but I am encouraging people especially back home, in the Philippines, to get the shot. If it’s available in your locality, take it but make sure you are well informed. Ask questions if you have an allergy, if you are pregnant or you have other special circumstances that might put you at risk.
Vaccination is only one step to end the pandemic. If you’ve been inoculated, congratulations! However, that doesn’t mean we all can go back immediately to our usual lifestyle. We still need to follow the advise of the experts. We still need to wear masks in public, observe social distancing, avoid crowded places and areas with poor ventilation. Follow the CDC guidelines and NHS recommendations.
By and large, I can only say that I am 95% protected because the virus mutates similar to influenza and since mRNA is a new method, I don’t know anything about its durability. We are still in a period where we are learning how these vaccines work. Yes, for now, we are safe but How long are we gonna to be protected? I guess time can only tell.
References:
https://www.nhs.uk/conditions/coronavirus-covid-19/coronavirus-vaccination/coronavirus-vaccine/
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vaccinated.html