How COVID-19 vaccine race .The Science behind Covid -19

PROTEIN SUBUNIT VACCINE Taiwan-based vaccine maker Medigen has produced a two-dose vaccine made of a combination of spike proteins and an adjuvant from Dynavax. The company began phase 2 trials in adults in late January 2021. In July, a phase 2 trial started on people aged 12 to 18 years old. In the same month, a phase 3 trial was authorized to be carried out in Paraguay. On 19 July, this vaccine was authorized for emergency use in Taiwan. A phase 2 trial was registered on 23 September 2021 to assess the immunogenicity of heterologous prime-boost immunization with AstraZeneca/University of Oxford (AZD1222) vaccine and Medigen (MVC-COV1901) vaccine in adults. The trial has plans to recruit 110 participants and is due to be completed in August 2022. The company started a phase 4 trial on 7 October to measure the level of antibodies produced in adults to demonstrate the immunogenicity and safety of the company's vaccine as a booster dose. A phase 4 clinical trial started on 7 October 2021 to measure the anti-SARS-CoV-2 neutralizing antibody titers in adult participants to demonstrate the immunogenicity and safety of a third booster dose with Medigen's COVID-19 vaccine. MODERNA (USA) RNA VACCINE The Moderna vaccine is also known as Spikevax or mRNA-1273. It was funded by the National Institute of Allergy and Infectious Diseases (NIAID), which is part of the US National Institutes of Health. The vaccine is administered in two doses four weeks apart. It was tested in phase 1 trials on volunteers at the Kaiser Permanente Washington Health Research Institute in Seattle. Moderna has run phase 2 trials on participants of a wide range of ages and started phase 3 trials in July 2020. The final trial enrolled 30,000 healthy people from across the United States. In February, a phase 4 trial was launched as part of a national cohort study in collaboration with the Danish Ministry of the Interior and Health. The United States currently authorizes its use for people 18 and older, while the Europe Medicines Agency authorized giving it to children aged 12 to 17 years in July. A phase 2 study was carried out in August 2021 to elicit an antibody response in kidney transplant recipients who have failed to respond to two doses of vaccine. This vaccine needs to be kept in refrigerators, or freezers for longer storage. The Faculty of Medicine Ramagthibodi Hospital in Bangkok, Thailand, under the sponsorship of the National Research Council of Thailand, registered a phase 3 trial in November 2021 to study the immunogenicity of an additional dose of either viral-vectored or mRNA vaccine in kidney transplant recipients. Another phase 3 trial was registered in November 2021 to study the safety and immunogenicity of a 9-valent HPV vaccine co-administered with Moderna's SARS-CoV-2 vaccine. A phase 1 trial was registered in November 2021 to determine the safety, reactogenicity, and immunogenicity of heterologous 3rd booster of mRNA and protein COVID-19 vaccines, including Pfizer/BioNTech's BNT162b2, Moderna's mRNA-1273 and Medigen's MCV COVID-19 vaccine. A phase 3 trial started in October 2021 to compare short and long-term immunogenicity of different COVID-19 vaccine combinations against the ancestral SARS-CoV-2 as well as different variants of concern. Involving 600 participants, the trial is due to be completed by April 2023. In November 2021, the company registered a phase 2 study to evaluate the immunogenicity and safety of the company's mRNA-1283 COVID-19 vaccine boosters to boost antibody responses to the ancestral strain of SARS-CoV-2 virus, the B.1.351 variant, and potentially other SARS-CoV-2 variants.