COVID-19 pandemic is the deadliest ever pandemic the world has ever faced in the modern era. Having no effective antiviral in place, vaccine is the only hope to get over the menace of SARS-CoV-2 virus. High mortality and emergence of variants made the entire world to put all its effort to prepare vaccine for this virus. For the first time in the history of medical science, vaccine was prepared in less than a year for any infectious disease. Currently, there are more than 20 vaccines for COVID-19 are already authorized by various national authorities and several more in pipe line (Table 1). Different vaccine technologies have been used for the development of COVID-19 vaccines such as nucleic acid (RNA or DNA vaccine), inactivated virus, live attenuated virus, non-replicating viral vector, recombinant protein, subunit or peptide, virus-like particle. Of these vaccine technologies, RNA vaccine came to use for human use for the first time for COVID-19 vaccine.

Table1. Details of SARS-CoV-2 vaccines

RNA vaccine: This works with the principle that the RNA segment containing the information to produce a specific antigen is inserted to plasmid. Plasmid containing this RNA is injected to host which is taken up by the host cell which then uses the RNA which then translated the protein or antigen. This in turn mounts the adaptive immune response and produces antibody.

The advantage of RNA vaccine is, it is safe as unlike DNA vaccine RNA does not possess the risk of integrating into the host cell genome. The production of RNA vaccine is simpler and rapid. However, the disadvantages are the risk of disintegration of RNA which is taken care by coformulation with lipid nano particle which protects the RNA strand and helps its absorption into host cell. Storage of RNA vaccine requires –70°C or –20°C depending on various modifications adapted to stabilize the RNA. Storage at this temperature is a major drawback for use of RNA vaccine in developing countries because of lack of availability of –20°C or –70°C deep freezer, stable electricity supply across the country.

Till date, two messenger RNA vaccine have got WHO approval for COVID-19. Pfizer BioNTech COVID-19 vaccine and Moderna vaccine.

Recommendation for vaccination: The current recommendation for COVID-19 vaccination is for all citizens above 18 years age unless contraindicated for medical reasons.

Vaccination in pregnancy: For women who are pregnant, the choice of vaccination is to be offered with the condition that the pregnant women may be informed about the risks of exposure to COVID-19 infection along with the risks and benefits associated with the COVID-19 vaccines available in the country. Risk of exposure to COVID-19 disease in pregnancy usually leads to severe infection and may affect the fetus whereas so far there is no evidence of any associated risk of vaccination during pregnancy.

Vaccination in children: The severity and mortality due to COVID-19 is much less in children as compared to adults. However, children do suffer from the infection and play important role in virus transmission and also though less they may suffer from severe COVID-19 and mortality also has been reported. So, it goes undisputed that children need vaccine against COVID-19. Pfizer-BioNTech’s mRNA BNT162b2 vaccine has been approved for 12–15 years. Vaccination in this age group is ongoing in many countries. Currently, trials are going on in children for several other vaccines in India; Covaxin, Bharat BioTech’s nasal vaccine, Zydus Cadila’s ZyCov-D and Novavax/Covavax.

The details of some of the widely studied vaccines are given in Table 1.

Other preventive measures: Mask, social distancing and use of sanitizer are the three most effective measures to prevent the acquisition of SARS-CoV-2 infection when followed properly.

اخر الاخبار

اخبار العتبة العباسية المقدسة

مؤتمر السيد المجاهد يشهد عرض فيلم وثائقي عن سيرته العلمية ومشروع إحياء تراثه

بحث حوزوي يتناول التمييز بين المعجزة والسحر عند السيد المجاهد

بحث يناقش أثر القواعد العقلية في استنباط الأحكام الشرعية عند السيد محمد المجاهد

بحث علمي يناقش ردود السيد المجاهد على اللغويين والنحويين في كتابه (مفاتيح الأصول)

المزيد

الآخبار الصحية

هل توقيت نشاطك اليومي يؤثر على صحة دماغك؟.. العلماء يجيبون

"مشروب محبوب" يخفي فوائد لا يعرفها كثيرون

طبيب يكشف 5 أنواع للسعال.. بعضها خطير

نقص فيتامينات "خفي".. قد يفسّر التعب والتنميل وقلة التركيز

المزيد

الآخبار التكنلوجية

دراسة: تغيّرات في أسلوب القيادة قد تكشف مبكرا عن الخرف !

عمرها 773 ألف سنة.. اكتشاف أقدم أحافير بشرية في المغرب

"اختراق علمي".. اختبار دم في منزلك قد يكشف ألزهايمر

ماذا يحدث للجسم عند قطع الكافيين فجأة؟

المزيد

مواضيع ذات صلة

Yellow fever Vaccine

HIV Vaccine

Vaccine of Poliovirus

Rubella virus vaccine

Vaccine of Measles virus

Vaccine of Influenza virus

Vaccination (Active Immunoprophylaxis)

Dengue Vaccine

Applications of Vaccines

Viral Vaccines

Microbiota, Chronic Infections, and Vaccines

Vaccines and the Role of Pre-existing Immunity