Monkeypox (mpox) virus belongs to the same family as variola virus causing smallpox. Usually spreading through skin-to-skin contact with the mpox-infected and causing rashes, this viral disease remained neglected before the recent (2022) outbreak. Although severity of the illness is high in the immunocompromised, the pregnant and the children, most of the infected recover in few weeks.However, the current mpox outbreak seems mysterious. The US has approved two vaccinia-derived mpox vaccines as preventives.The CDC recommends ACAM2000 only as an alternative to JYNNEOS for infants (of 1 yr age) and older that are at high mpox infection risk. The common side-effects of both the vaccines are injection-site reactions, headache, muscle pain, fever, chills, fatigue, nausea and altered appetite.A total of 276 participants received single dose ofthe vaccine 11 days after mpox exposure. Mpox infection developed in 12 recipients, of which 10 recipients manifested itin 5 days, 1 in 22 days, and 1 in 25 days after vaccination.However, no severe adverse events or safety concerns were noticed. The recipients that did not develop mpox infection received the second dose after 29-day median. The two participants that manifested breakthrough infections by the 22nd and 25th day had a pet (cat and dog) at home, both the pets although were asymptomatic.However, important limitations of the study were, it was carried out at a single center, them pox exposure was not assessed, and the study did not consider a control group or measures of vaccine-elicited immunity.No verifiable data on the efficacy of JYNNEOS or ACAM2000 against mpox is available yet. To determineits efficacy in the ongoing outbreak better, an open call for international studies on mpox vaccine is urgently contemplated.Considering mutations, the vaccine side effects and break-through infections, developing a mutant-proof, nex-gen vaccine for mpox virus that may be more effective and safe is recommended.