The Summer Games are scheduled to begin on 23 July, after being delayed by 12 months because of the Covid-19 pandemic.
The International Olympic Committee said vaccination is "encouraged" but not compulsory for athletes.
Guam, Marshall Islands, Federated States of Micronesia, Palau, American Samoa, Australia and New Zealand have begun vaccination programs in recent months.
Oceania National Olympic Committees (ONOC) President, Dr Robin Mitchell, said if athletes had the option of receiving the vaccine they should take it.
"During the Forum Leaders meeting a couple of weeks ago, I sent through a message to the chair of the forum...to request that where possible after the primary targets in each country, that consideration be given to the athletes and this I understand was supported by the meeting," he said.
"The way we've put it is that we're looking at the entourage which generally would be head of state, head of government, minister of sport, plus the athletes and all the officials.
"The possibility is it's reasonable, I think, for all of us to be covered so we can get into Japan. We don't need vaccinations to get in at the moment but at least when we are vaccinated and we come back we're not bringing the bugs with us and then there's a two week quarantine as well."
Pacific Island nations are expected to send about 150 athletes to the Tokyo Games although the closure of international borders and cancellation of sporting events continues to hamper preparations.
"Basically our borders are closed in at least 10 of the NOCs in the southern part of the Oceania region and at various stages of the sport," Dr Mitchell explained.
"Currently half our group don't have access to training facilities so it's a difficult one for those in that position."
Many sports are still trying to complete their Olympic qualifying process, with close to 35 percent of athletes' spots are still up for the taking worldwide.
But for the majority of athletes in the region travel restrictions have forced them to continue their training in-country.
Even if athletes are ready and able to compete, Mitchell said getting off the ground and to a competition was not always possible.
"Some of the different countries have had their athletes going to university in Japan so they have stayed on. With Japan's current state of emergency if they go out they can't get back in again so they're not going to qualifying tournaments.
"For example there's three judokas in Japan: a Fijian, a Guam male and a Kiribati female, so they're all training there at the moment but it's to get to the qualifying tournaments to get the necessary points."
ONOC is in regular communication with all of its members and Mitchell said no athletes in the region had expressed any concerns about travelling to Tokyo.
"In the surveys of athletes people are not talking about whether the Games are on or not - they're just asking questions of access: what if this happens? Will my chef be able to go there?
"For a lot of the bigger teams a lot of their support staff are staying outside of the (athletes village) - how do they get in because there's no guest passes available at the moment? There's a lot of grey areas that probably won't be clarified until a month out."
The Australian and New Zealand governments both offered assistance to Pacific Island nations in their preparations for Tokyo, while ONOC distributed an initial $US25,000 to all its 17 member countries, as part of a one million dollar grant from the Association of National Olympic Committees (ANOC), which will help countries to organise training camps before the Games start in July.