Events are happening around the globe to mark World AIDS Day.
The theme for 2015 is a campaign to "End AIDS by 2030".
People are being urged to express their solidarity by wearing a red ribbon, challenging stigma and by getting tested for HIV.
City Councils around Ireland are lighting up prominent buildings in red to mark the start of a five day national campaign promoting HIV awareness.
In Ireland, the latest figures show an 11% increase in the number of new HIV cases - with the age profile getting younger.
What are the statistics for HIV?
According to the World Health Organisation, HIV continues to be a major global public health issue, having claimed more than 34 million lives so far. In 2014, 1.2 [980 000–1.6 million] million people died from HIV-related causes globally.
An estimated two million individuals worldwide became newly infected with HIV in 2014 while 2 million people died from AIDS-related causes in 2014.
36.9 million people living with HIV globally, 17.1 do not know they have the virus and need to be reached with HIV testing services, and around 22 million do not have access to HIV treatment, including 1.8 million children.
Get tested
Tiernan Brady of the Gay and Lesbian Equality Network (GLEN) says the organisation is trying to encourage people to get tested by setting up mobile clinics in clubs and workplaces.
"People don't look forward to getting a HIV test, so we need to provide testing in new venues in ways that is free, that's accessible, that's non-clinical and that will give you the result immediately" he said.
"And the new testing pilot - which GLEN are running, which the minister has announced - is a really brilliant step forward in that regard" he added.
Sandy is the chairman of Positive Now, and has lived with HIV for 17 years.
He says that he was given just two years to live, but it has now become a part of his daily life.
Drag artist Rory O'Neill - aka Panti Biliss - is HIV positive for the last 20 years. He told Newstalk Breakfast it is no longer a life sentence.
Michel Sidibé, UNAIDS executive director, talks about World AIDS Day 2015:
British Prime Minister David Cameron said health authorities in the UK are offering home testing kits:
While AIDS-fighting charity RED has launched a new campaign featuring Scarlett Johansson, Barry Manilow and US TV host Jimmy Kimmel.
The trio produced a jingle to encourage people to take part in the organisation's 'shopathon' and raise money to help eradicate AIDS.
(RED) SHOPATHON: Scarlett Johansson, Barry Manilow, Jimmy Kimmel
SHARE this (RED) #SHOPATHON Jingle with Scarlett Johansson, Barry Manilow & Jimmy Kimmel and Bill & Melinda Gates Foundation will donate $3 to (RED), up to $1 MILLION! Watch the (RED) #SHOPATHON in partnership with VICE on Jimmy Kimmel Live World AIDS Day December 1.
Posted by (RED) on Monday, 30 November 2015