Reuters reports that conspiracy theories about vaccines are so entrenched that even frontline health workers are hesitant to take the shot, Wong said at a talk with an Australian think-tank that was streamed online.
"Facebook is our biggest conspiracy theorist platform," Wong said at the Lowy Institute talk, adding people should not rely on unverified claims on Facebook to guide their approach to vaccines.
"Facebook has a lot of influence here. They are supposed to have programmes where they stop these types of things. Facebook must take responsibility of this and stop it."
False claims and conspiracies have proliferated on social media platforms during the pandemic, but distrust in PNG is unusually deep-seated, local health leaders say, hurting the island's prospects of recovery as infections spike.
Facebook Inc is committed to removing "false claims about the safety, efficacy, ingredients or side effects of the vaccine, including conspiracy theories", its director of public policy for Australia, New Zealand and the Pacific islands, Mia Garlick, said in an email.
"Conversations about vaccines tend to be nuanced, so we're continuing to work with health experts, including the World Health Organisation, to make sure that our approach and our policies are in the right place," she added.
Still, peddlers of bogus claims continue to evade Facebook's policing by disseminating their views via comments beneath legitimate news items, experts noted.
"Someone will post a story as simple as the prime minister being vaccinated ... and then the comments that come under it, it just turns into this frenzied discussion," David Ayres, country director for family planning clinic Marie Stopes, said by telephone from Port Moresby.
Ayres said in his organisation, about 40 out of 100 employees were opposed or reluctant to take the vaccine.
"When those people are interacting in their community, interacting with their family, it's promulgating these messages that we really shouldn't be giving any oxygen at all."
Bridgette Thorold, country director of child services non-profit ChildFund PNG, said even if there were enough vaccines for PNG's 10 million people, many would refuse due to misinformation.
To reassure citizens about vaccines, Wong, Prime Minister James Marape and several other PNG officials have taken the AstraZeneca vaccination.
While PNG will not make vaccination mandatory, it should have enough shots in the next three or four months for everyone who wants to be vaccinated, Wong said.
PNG has so far received 8000 vaccine doses from Australia's supply.
India, the world's biggest vaccine maker, has promised another 70,000 doses, but deliveries could be delayed as it has since put a temporary hold on all major exports of the AstraZeneca shot to meet domestic demand.
China has committed 200,000 doses for its citizens in PNG.
PNG also expects 588,000 doses by June under the COVAX initiative to help poorer countries, but there are doubts about supplies given export curbs by producing countries.
Save the Children has added its voice about the massive spike in misinformation and fake news which is undermining efforts to bring the outbreak under control.
NGO and health workers on the ground in PNG have described the misinformation as spreading faster than the coronavirus itself.
Save the Children PNG is helping to combat the misinformation through a series of targeted radio advertisements. The organisation is running three different bulletins that clarify how Covid-19 is spread, how to reduce the risk of contracting it, and pandemic parenting tips for caregivers and parents.
Save the Children PNG country manager Gerry Dyer said: "We've seen around the world the dire consequences fake news and misinformation can have in the middle of a pandemic.
"What we are seeing in PNG is a tsunami of misinformation about the virus and the vaccine that will cost lives.
"People may encounter a social media post containing misinformation, and then repeat it in the real world as established fact. This is dangerous when accurate information is key to stopping the spread of the virus.
"The first step in countering the misinformation is to call it out and demand a better standard from social media companies.
"The second step is to arm every PNG citizen with all the facts so that we can become truth ambassadors.
"Save the Children PNG is using national, provincial and local church radio stations to help give people the information they need to protect themselves and their families.
"Radio works well in countering misinformation as people trust the medium and it is accessible to remote communities.
"The misinformation is coming from every direction and spreading faster than the virus itself."
Save the Children used radio bulletins in 2020 to reach an estimated 1.1 million people across PNG with important public health messages.