Updated Nov 2022
As many countries have approved COVID vaccines for emergency use and mass vaccination drives, it is a moment of global pride and a celebration of science and medicine. Also coming with this are apprehensions and concerns. Therefore keeping these 5 points in mind can be useful and reassuring.
ARE THE COVID VACCINES SAFE?
All the vaccines which have got emergency authorization and approval in different countries are generally safe in the majority of population. They have been tested in thousands of people through clinical and real-world studies and the data has been carefully scrutinized by the regulatory authority of each country.
COVID vaccines (like the vaccines for other infections being taken over several years) can cause reactions in some people, like local injection site pain, stiffness, swelling, or irritation, and some general symptoms like fever, body ache, headache, tiredness, and weakness. However, these are usually mild and resolve in a day or two. Ice can be applied on the injection site and paracetamol may be taken if needed.
Severe allergic reactions are very rare (1-10/million), and mostly in people with a prior history. They are manageable with anti-allergic medications available at vaccination centers. Vaccine-related neurological effects (like Bell’s palsy, Guillain-Barre syndrome, and transverse myelitis) are also very rare and in many cases do show resolution.
Some reports of cases of thrombosis (blood clots) especially in young women with adenoviral vaccines have raised concerns but the incidence in those vaccinated is lesser than or comparable to that seen in the general population. VITT (vaccine-induced immune thrombotic thrombocytopenia) also called thrombosis with thrombocytopenia syndrome (TTS) is a serious adverse effect characterized by simultaneous acute thrombosis and thrombocytopenia (fall in number of platelets) that can even lead to death, and can occur between 5-45 days post vaccination.
There have also been few reports of myocarditis post mRNA vaccine in young males however that was found to be transient in most cases without serious sequelae.
Another reported complication post COVID vaccination is Multisystem Inflammatory Syndrome (MIS) which though rare, can be fatal, and sets in 3-4 weeks post vaccination.
There are limited studies on the safety of vaccines in pregnant or lactating women, however, vaccination is of significant importance in these groups as they are vulnerable to more severe COVID if infected. The USFDA/CDC has permitted the use of its approved vaccines in pregnancy and lactation after individual risk evaluation and proper counseling. Similarly, the MoHFW India and many other countries have also released guidelines for use of their approved vaccines in pregnancy and lactation. COVID vaccines have also now been approved for use in children after clinical trials in younger agegroups.
Even though the adverse effects listed above may cause apprehensions, the benefits of COVID vaccination still far outweigh the risk of suffering from COVID which can lead to complications, hospitalization, death, or long-term health concerns.
However it is important to be aware of all information related to AEFI (adverse effects following Immunization) and make an informed choice.
HOW DO WE KNOW THAT THE COVID VACCINES WORK?
All the vaccines which have got emergency authorization and approval in different countries have done so only after testing that the vaccine works by generating adequate protective immunity in the form of antibodies and other cytokine immune markers against COVID in phase 2 studies in hundreds of people. The data of these studies are either already available in public domain, or in process of publication.
Vaccine effectiveness shown by vaccinated people not getting COVID, needs a long duration of monitoring and surveillance in a large population. Even so, phase 3 studies for such evidence in thousands of people were conducted and the efficacy results made available to regulators before vaccine approval
It is evident that the vaccines that showed an adequate immune response in phase 2, also showed efficacy in phase 3 with immunogenicity being a surrogate marker of efficacy and effectiveness. Therefore, some vaccines were given emergency authorization based on their immunogenicity and safety data, so that they can be beneficial during the pandemic to meet mass vaccination needs. However, in all such cases, phase 3 was ongoing and subsequently completed, with the data being further constantly monitored.
As of now, there is no evidence to suggest that the vaccines will not work against variant strains, though the absolute level of immunity developed may vary as that is based on both neutralizing antibodies as well as T-cell response. In case of drastic mutations occurring in the future in the COVID-19 virus, the vaccines may be suitably updated. As of now, vaccines are still the most effective way of preventing severe disease, hospitalization, complication, and death even with respect to COVID variants including the Omicron and its subvariants. In August 2022, bivalent updated mRNA COVID vaccines that target both the original COVID strain and the Omicron strains (BA.1 or BA.4/BA.5) have been developed and approved.
Some vaccines with stringent storage conditions may not be feasible in certain countries which may have to opt for vaccines easily storable in a regular refrigerator at 2-8 deg C. Also, it is difficult to vaccinate the entire population of some countries with imported vaccines alone, therefore indigenous or collaborative vaccine development and manufacturing hold the key to catering to large-scale successful vaccination drives.
CAN ONE GET COVID AFTER BEING VACCINATED, AND ARE MASKS AND SOCIAL DISTANCING STILL NEEDED?
The optimal protective immunity is seen to set in around 10-14 days after the final vaccination dose. Therefore, till then you may be at some risk of getting COVID. The precautions of wearing masks in public, social distancing and frequent hand washing and sanitizing may be enforced by countries in various degrees based on the percentage of the population vaccinated, and the local COVID spread.
Even post-vaccination, one can be an asymptomatic carrier so one may not suffer COVID but can give it to someone who is previously unexposed or does not have protection by either natural immunity or vaccine. Therefore to reach the stage of pre-COVID normalcy, more and more people will have to take the vaccine to achieve effective herd immunity. Many countries have now done away with mask and social distancing mandates, as well as testing requirements for travel.
No vaccine can give 100% protection, but even if one does get symptomatic COVID, it would be mild, avoiding the risk of complications, hospitalization, and mortality.
Boosters: The immunity has been seen to last for 6 months and possibly up to a year, however, this is still being monitored and evaluated by regular follow-up of clinical trial participants and vaccinated groups. Some countries have recommended and started booster doses for adults and even children after 6 months of the last vaccine dose, while other countries like India have started boosters for adults after 9 months of second primary dose. Focus continues on giving the primary 2 doses of the vaccine to the entire adult and pediatric population.
IS IT COMPULSORY TO GET VACCINATED?
Vaccination against COVID is entirely voluntary and should be opted for after being satisfied with the information available on its safety and benefit.
However, it is highly recommended for everybody to get vaccinated for personal protection against suffering from severe COVID and its sequelae.
Health care workers and front-line workers should all be preferably vaccinated. Elderly people and those with co-morbidities like diabetes, hypertension, heart/kidney/liver ailments, respiratory conditions, reduced immunity post-transplant or HIV, etc. should take the vaccine as they are more prone to developing severe COVID and its complications if infected.
Even those who have already suffered from COVID, can take the vaccination at 3 months post-recovery.
It is also important to get vaccinated for attaining herd immunity in the community as more and more people getting vaccinated can reduce the virus spreading even in the unvaccinated population.
Vaccination is only possible at designated COVID vaccination centers by prior registration, but to increase convenience and coverage, walk-in registration and vaccination is being encouraged.
Vaccination is now a travel requirement by the government in most countries and is also considered an entry pass to many public places and transport. It has also been made mandatory for sports events, and for the staff of many essential services and organizations.
Other vaccines if recommended, other than COVID should be given with a gap of 2 weeks (preferably 4 weeks for live vaccines) before/after the COVID vaccine dose. Post-vaccine, blood donation can be done after a gap of 14 days.
HOW DOES ONE DECIDE WHEN AND WHICH COVID VACCINE TO TAKE?
One should register on the country’s official vaccine platform as soon as the same is open or visit the nearest COVID vaccination center. Thereafter one gets the vaccine in accordance with prioritized high-risk groups and vaccination protocols. The vaccination centers are organized and well equipped to manage socially distanced queueing and waiting, administration of the vaccine by a qualified health care worker, and post-vaccination observation for reactions. Notification for 2nd dose and booster, and certification of completed vaccination are also incorporated in the process.
One should take whichever vaccine is available and not wait or make attempts to procure a particular or alternate vaccine, as this can not only disturb the organized vaccination system and process of the country, but also not confer any potential advantage or benefit.
COVID vaccines are given as injections, however recently in India, a recombinant replication-deficient adenovirus vector vaccine with a prefusion stabilized spike protein has been developed as an intranasal vaccine (nasal drops).
CURRENTLY APPROVED COVID VACCINES FOR EMERGENCY USE:
There are 47 approved COVID vaccines globally (the important ones are listed below).
Most vaccines are taken as 2 doses, 4 weeks apart, however vaccine availability and population load can be factors that induce variability. For Astra Zeneca-Oxford (Covishield) up to 12 weeks gap between doses is being practiced in some countries. Johnson and Johnson is currently a single-dose vaccine, and ZyCoV-D is a three-dose vaccine.
Most vaccines are currently for 18 years and above (pediatric approval mentioned for individual vaccines). Of the vaccines mentioned below, 11 (Pfizer-BioNtech, Moderna, Oxford-AstraZeneca, Covishield, Covaxin, Johnson and Johnson, Nuvaxovid, Covovax, Coronavac, Cansino, and Sinopharm) are WHO approved and recognized.
- Pfizer-BioNtech mRNA vaccine BNT162b2 /Comirnaty: Approved in 149 countries including USA, UK, EU, Canada, UAE, Singapore, etc. Authorized for children 5 years + children by USFDA.
- Pfizer/BioNTech Comirnaty Bivalent Original/Omicron BA.1 approved in 32 countries including UK and EU. Pfizer/BioNTech Comirnaty Bivalent Original/Omicron BA.4/BA.5 approved in 32 countries including USA and EU.
- Moderna mRNA-1273 vaccine (Spikevax): Approved in 88 countries including USA, EU, UK, Canada. Authorized for 12 years + children in UK, EU, Canada and Japan.
- Moderna mRNA-1273.214 vaccine (Spikevax Bivalent Original/BA.1): Approved in 38 countries including UK, Ausralia, Canada and EU. Spikevax Bivalent Original/BA.4/BA.5 is approved in USA.
- Oxford-Astra Zeneca non-replicating adenoviral vector vaccine AZD1222 (Vaxzevria): Approved in 149 countries including UK, EU. Covishield -India in collaboration with Serum Institute, Pune is approved in 49 countries and as part of India’s vaccine diplomacy).
- Sputnik V Adenoviral vector vaccine: Approved in 74 countries including Russia, and UAE, and in India in collaboration with Dr. Reddy’s Labs. Single-dose Sputnik light (single dose) is approved in 26 countries including Russia.
- Johnson and Johnson Adenoviral vector vaccine AD26.COV2.S: Approved in 113 countries including USA, EU.
- CanSino Ad5-N-CoV Adenoviral vector vaccine: Approved in 10 countries including China.
- Covaxin Bharat Biotech-ICMR-NIV inactivated vaccine: Approved in 14 countries including India. Authorized for 12 years and above.
- Coronavac -Sinovac inactivated vaccine: Approved in 56 countries including China. Authorized in China for 3 years and above children.
- Sinopharm inactivated vaccine BBIBP-CorV: Approved in 93 countries including China, and UAE. Authorized for 3 years and above children in China and some countries.
- NVX-CoV2373 (Nuvaxovid) protein subunit vaccine from Novavax: Approved in 37 countries across EU, and as Covovax from Novavax-Serum Institute in 6 countries including India. Authorized for children 6 years and above.
- Corbevax protein subunit vaccine developed by BioE India and Baylor College of Medicine, USA: Approved in India and Botswana. Authorized for 12 years and above.
- ZyCoV-D needle-less intradermal 3-dose DNA plasmid vaccine from Zydus-Cadila: Approved in India for 12 years and above.
- Gemcovac-19 mRNA vaccine from Gennova: Approved in India.
- iNCOVACC (BBV154) recombinant non-replicating adenovirus vectored intranasal vaccine from Bharat Biotech: Approved in India
Register on your country’s COVID vaccine platform or portal as soon as possible.
Many countries have formed collaborations of their local manufacturing companies with international innovators. As of May 2022, around 12 billion vaccination shots have been given globally in more than 184 countries with various COVID vaccines. As part of GAVI (Global Alliance for Vaccines and Immunisation, WHO), the COVID-19 Vaccines Global Access (COVAX) is acting as a platform to support the research, development, and manufacturing of a wide range of COVID-19 vaccines to ensure that participating countries, regardless of income levels, will have equal access to these vaccines once they are developed.
COVID Vaccine trials:
Astra Zeneca- Oxford Adenoviral vector vaccine
Astra Zeneca-Oxford vaccine pooled analysis
COVISHIELD and COVAXIN – India
India COVID Vaccination – Real-world survey evidence
Sputnik V human Adenoviral vector vaccine
Johnson and Johnson Adenoviral vector vaccine
Novavax-Nuvaxovid NVX-CoV2373 phase 3
ZyCoV-D phase II and phase III approval
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2 Comments
The article puts lots of doubts and apprehensions to rest. The advantages of taking the vaccine are explained in a very lucid manner.
Thank you Dr. Varsha for such a timely article .
Very Well explained. Great.