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As we lean into 2021, hope is definitely looming in the background. As an emergency medicine physician working in the frontlines in the US, I was fortunate to receive the first dose of the Pfizer/BioNtech Covid-19 vaccine on Dec 15. Nepal will likely get its first vaccines in the next few months. Facts about vaccines are evolving daily, and there is a plethora of information going around. I hope to clarify some of your vaccine-related concerns.


There are three top vaccine candidates that could be available in Nepal in the near future: the Pfizer/BioNtech vaccine, the Moderna vaccine, and the AstraZeneca vaccine.  These vaccines have recently completed the important Phase 3 trial, which assesses their effectiveness in a large population, and some have been authorised for emergency use in multiple countries. From the early data available from these three trials, some key differences between these leading candidates must be understood.

Pfizer/BioNTech: This mRNA vaccine can be stored for 6 months at minus 70 degrees Celsius, and for 5 days at minus 4 degrees Celsius. The vaccine is given in 2 doses, 21 days apart. This vaccine has shown up to 95% effectiveness in preventing the Covid disease and lowering symptoms, and no severe side effects were seen in the studies.

Moderna: This mRNA vaccine can be stored for one month at minus 4 degrees Celsius. The vaccine is given in 2 doses, 28 days apart. This vaccine has shown 94% effectiveness in preventing the Covid disease and lowering symptoms, and no severe side effects were seen in the studies.

AstraZeneca: This DNA vaccine can be stored at 2 to 8 degrees Celsius. The vaccine is given in 2 doses, 28 days apart. This vaccine, which has been approved for use in the UK, has shown mixed results in different countries, but has an average of 76% effectiveness in lowering infectivity of the Sars-COV2 virus. No severe side effects were seen in the studies.

An important difference to note is that the Pfizer and Moderna vaccines assessed disease severity as their endpoint, whereas AstraZeneca assessed lowering of infectivity as their endpoint. Additionally, the AstraZeneca vaccine can be stored at higher temperatures and is cheaper compared to the other two vaccines, and this is likely going to be the reason Nepal will have mostly AstraZeneca vaccines available in the upcoming months and years. Other vaccine candidates like Johnson and Johnson will likely complete their Phase 3 trial in the upcoming months, and they could expedite worldwide availability of their vaccines. AstraZeneca provides the biggest hope for mass vaccine availability in Nepal due its lower price and easier storage conditions.


As one of the first Nepali-Americans to receive this vaccine, I feel truly fortunate; but doubts about this vaccine and other Covid-19 vaccines are rampant. In the US, where priority is given to healthcare workers and the elderly, there is a climate of mistrust of the vaccine and the spread of unfounded misinformation continues. The science so far is quite clear: these vaccines are safe. Yet, the prevalence of people opting out of vaccination programmes is high, and severe doubts about the vaccines exist among the American public. When the vaccines do come to Nepal, we must prepare for such attitudes, and try to understand why these doubts exist. There are a few key reasons that I have seen causing this doubt.

1) How did these vaccines become available in such a short period of time?

This is one of the biggest points of concern. One of the fastest vaccines manufactured and available was the mumps vaccine, whose development took four years; most vaccines take years to be manufactured and be made available, so how did the Covid-19 vaccines come out within a year? This is a fair question to ask, and understanding the key factors behind vaccine production is important. Two factors play a major role in any vaccine production: financing and prior research/knowledge. Typically, budget availability is a major hurdle in vaccine completion, and each step of vaccine production requires a budget re-evaluation. Fortunately, for the Covid-19 vaccines, due to global collaboration and effort, most companies working on them were able to secure funding to move forward with each phase of their trials. In fact, most developed countries pre-ordered vaccines from these companies. Financing their research was not an issue for these companies.

Prior knowledge of a certain virus or a vaccine type can also help make the manufacturing process faster. Tremendous amounts of research and knowledge of coronaviruses and mRNA technology exist as a result of past efforts. Our world has already seen outbreaks of coronaviruses like the 2002 Sars-CoV (severe acute respiratory syndrome coronavirus) and the 2012 Mers-CoV (Middle East respiratory syndrome coronavirus), and the process of creating vaccines against these viruses has already taken place. For example, the 2002 Sars-CoV vaccine was created and tested in a Phase I trial, but its development was stopped because the virus was eradicated. That provided a headstart in the development of a vaccine against the Covid-19 virus. Additionally, mRNA technology has been around for a long time, especially in cancer-related research.

2) What if there are bad side effects from the vaccines?

The Phase 4 part of vaccine trials, which entails looking at the vaccines’ effects and monitoring severe outcomes once they go to the market, will take a number of years. In medical science, most therapy decisions are made on the basis of risk-benefit assessments. Considering the risk and benefits of this vaccine, I have deemed (as have many regulatory bodies and scientists) that it has more benefits than risks in the case of the Covid disease.

There is, however, general fear and misinformation regarding its potential effects. The Pfizer and Moderna vaccines are mRNA vaccines, and this technology is deemed much safer. The mRNA vaccines directly build a specific protein (the spike protein), and allow our immune system to make antibodies. Eventually, if a Sars-Cov2 virus is presented, our body will be able to recognise the spike proteins and act against them. The trials data presented above also reaffirm this safety. In the US, unfounded claims of these vaccines causing severe side effects have been a major cause creating doubt among the public.


As soon as the Pfizer/BioNtech Covid-19 vaccine was made available, I opted to receive this vaccine. I have seen enough people die from the Covid-19 virus, young and old, and my understanding of how severe and scary the disease can be is why I was easily able to make this decision. On the first day after I got vaccinated, I was mildly tired and warm, but this an expected part of our body’s immune response. Today, on the 15th day since I got the vaccine, I feel great, and I will be getting my second dose on January 5, 2021.

With news of new strains of Covid-19 spreading around the world, there is also concern that these vaccines might not work. New strains are expected with any virus, as it continues to mutate over a long period of time. That’s why the vaccine manufacturers built their vaccines with this anticipation. A lot is yet to be known, but most likely, the vaccines will be effective even against these new strains. The vaccines represent a scientific win for our world, and the opportunity will soon arrive for Nepal to get vaccinated too.

My hope and prayer for 2021 is that everyone in Nepal and around the world gets the opportunity to get vaccinated. In the meantime, keep your faith, keep wearing your masks, wash your hands, and stay informed!

References for this article are available upon request.