COVID-19 has emerged as a global threat across the world. Apart from antivirals, immunotherapy is considered to play an important role against the virus. The immune evasion strategy of SARS- CoV-2 suppresses interferon induction. The new different immunotherapeutic approaches for COVID-19 include immunization through vaccines, interferon administration, passive immunotherapy by convalescent plasma or monoclonal and polyclonal antibodies.
In several clinical trials, positive results were found by using interferons type I, including interferon-beta-1a in several clinical trials. Interferon-beta is already being examined in a combination protocol in the international clinical trial launched by WHO, called the “Solidarity” trial. Vaccines are believed as the ultimate protection for saving the public from the novel virus. A possible strategy against COVID-19 apart from anti-virals and vaccines is neutralizing antibodies. Antibodies can either be given in the form of convalescent plasma or produced in the lab. The plasma therapy approach is being used and investigated in many countries with acceptable levels of success.
On the other hand, different polyclonal or monoclonal antibodies could be produced via using hybridoma cell-lines, animals, or cell-free protein synthesis, which may be administered in patients as a monoclonal antibody or a cocktail of antibodies. In addition to inhibiting the virus entry, antibodies can intrude into the biological activities of the virus thereby preventing its replication.
A recent study revealed that the antibodies targeting receptor-binding domain (RBD) of the coronavirus family are virus species-specific, while those that target viral parts outside RBD are capable of cross recognition. Several classes of immunomodulators including tyrosine kinase inhibitors, mTOR inhibitors, calcineurin inhibitors, antimetabolites, TNF blockers, metal-based agents, and other anti-inflammatory agents might be of value in the treatment of COVID-19. At later stages of critically ill COVID-19 patients, such immunomodulators might be potentially life-saving.
Ref link: https://pubmed.ncbi.nlm.nih.gov/32877828/