COVID19vacciner

COVID19vacciner refer to the various vaccine products developed to protect people against infection by the SARS‑CoV‑2 virus, which causes coronavirus disease 2019 (COVID‑19). The first vaccines received emergency use authorization in late 2020, after rapid development and clinical testing that demonstrated acceptable safety and efficacy profiles in large, diverse populations. Since then, several platforms have been used, including messenger RNA (mRNA) vaccines, viral vector vaccines, inactivated virus vaccines, and protein subunit vaccines. Well-known examples of mRNA vaccines are the products developed by Moderna and Pfizer‑BioNTech, while viral vector vaccines include those from Oxford‑AstraZeneca and Johnson & Johnson. Inactivated virus vaccines, such as those produced by Sinovac and Sinopharm, and protein subunit vaccines, such as Novavax, are also widely distributed in many countries.

COVID19vacciner are typically administered in two doses, with a single-dose variant available for certain viral vector products. Booster shots are recommended for populations at higher risk—older adults, immunocompromised individuals, and people in high‑infiltration areas—to enhance waning immunity and protect against emerging variants. The vaccines have shown significant reduction in severe disease, hospitalization, and death, although they are less effective at preventing infection with highly transmissible variants like Omicron. Common side effects include mild injection‑site pain, fatigue, headache, and fever, and these reactions usually resolve within a few days. Severe adverse events are rare and are monitored continually by regulatory authorities. Global vaccination campaigns have contributed to a notable decline in COVID‑19 case numbers and mortality rates worldwide.