A lavish hero's welcome for Filipino boxing sensation Manny Pacquiao may not be possible anytime soon after the World Health Organization on Wednesday joined calls to postpone Pacquiao's planned victory parade in Manila to prevent the possible spread of the influenza A (H1N1) virus.

In a letter to Health Secretary Francisco Duque, the WHO gave Pacquiao two options: delay his and his entire entourage's return to Manila for five days; or quarantine themselves and postpone their victory parade if they choose to return on Friday.

For the first option, WHO said Pacquiao and his entire entourage should delay their flight from Los Angeles, California to Manila for at least five days and to limit their movements to their hotel rooms or residential house.

"The five days will serve as observation period for any possible person getting sick with flu like signs and symptoms so that proper preventive and control measures can be instituted to the whole entourage," the WHO letter read.

It added that if Pacquiao chooses to return to Manila on May 8, he and his entire entourage should be briefed on proper social distancing measures, personal hygiene and etiquette including observation of flu-like signs and symptoms for a period of five days. It said the orientation can be done in the US or in Manila before they are release by immigration authorities.

"In both options, social distancing should be practiced at the airport of departure and airport of arrival. The welcome greeters in Manila should be kept at a distance of at least one meter and no handshake or any form of social greetings like hugging or kissing," it added.

The WHO said members of Pacquiao's entourage who are not ill during the time of arrival should be encouraged to observe any signs of illness for a period of five days and inform immediately the Department of Health if there are any symptoms.

"It is also advised that Mr. Pacquaio forego his motorcade and various parts of the country as a contuining measures of social distancing. He may postpone it for at least five days after arrival. Likewise, victory parties should also be postpone for the same duration," the WHO said.

The WHO said the precaution is necessary after US health authorities established human-to-human transmission of the A (H1N1) virus with third generation spread in the US, specifically in Los Angeles where Pacquiao and his entourage stayed.

Pacquiao is due to fly back Friday from Los Angeles after his sensational two-round knockout of light-welterweight king Ricky Hatton in Las Vegas last weekend.

Duque earlier said the government wanted Pacquiao to put off his return for five days until next Tuesday due to fears he or members of his entourage may have contracted the influenza A (H1N)1 virus.

That delay corresponds to the period during which an infected human would display symptoms of the virus, he added.

Authorities said they were taking seriously the risk of the virus spreading during a planned Manila parade for the Filipino southpaw, who has now won six world titles at different weights, and which is expected to be watched by tens of thousands of people.

Duque also counseled that Pacquiao "should not be going out anymore," and that he and members of his homecoming party "should impose self-quarantine."

According to the latest WHO figures, 1,490 people around the globe have been infected by swine flu. Mexico says 29 died there, while two fatalities have been reported in the United States. With Agence France-Presse